OCT-Comprehensive Eye Examination

Problems in the eye or brain can affect vision. It is accepted that all children should have a screening exam. Adults above 45 years must also have a yearly check. An eye exam is one of the best ways to protect your vision because it can detect eye problems at their earliest stage — when they’re most treatable. Regular eye exams give your eye doctor at Darshan Eye Clinic a chance to help you correct or adapt to vision changes. Your eye care specialists can also give you expert tips on reducing eyestrain and caring for your eyes.

What is a comprehensive eye examination? Read more…

Facilities at Darshan Eye Clinic for a comprehensive eye examination:

  • Electronic Chart Projector
  • Autorefractokeratometer
  • Retinoscope
  • Slit Lamp Biomicroscope with digital image recording system
  • Ishihara Chart for Colour Vision
  • Direct and Indirect Ophthalmoscope
  • Special Lenses for studying the retina and optic nerve

Cataract and Intraocular Lens Implant Surgery

Our eyes have a natural clear lens that allows images of our world to be focused clearly on the retina – the light sensitive screen at the back of the eye. With age, (and rarely due to other causes), the natural lens loses its clarity. This change is called a cataract and it causes blurred vision. Cataract surgery is quick and painless. The cataract is removed through a very small opening (that closes without stitches). A foldable intraocular lens that is inserted greatly improves the quality of vision and minimizes the need for glasses.

What is the state-of-the-art phacoemulsification surgery? Read more…

Facilities at Darshan Eye Clinic for Cataract and Lens Implant Surgery:

  • A Scan Ultrasonography
  • Keratometry
  • Digital Biometric Ruler (DBR)
  • B_Scan Ultrasonography
  • YAG laser for posterior capsulutomy

Refractive Surgery

Light rays can be made to focus properly on the retina by using glasses, contact lenses, or by a variety of surgical methods. Refractive eye surgery is any eye surgery used to improve the refractive state of the eye and decrease dependency on glasses or contact lenses. The most common methods today use the excimer laser. Other surgical procedures require the use of heat to shrink the cornea selectively (conductive keratoplasty), or implant material in the cornea to change its shape (intrastromal corneal ring segments), or the implantation of a lens inside the eye (phakic intraocular lens) or replacement of the natural lens with an intraocular lens (clear lens extraction).

How does successful refractive eye surgery eliminate common refractive errors such as myopia, hyperopia and astigmatism? Read more…

Facilities at Darshan Eye Clinic for Refractive Surgery:

  • Allegreto Wave Excimer Laser access
  • Corneal Topography
  • Corneal Pachymetry

Corneal and Scleral Disease

The cornea and sclera form the protective shell for the delicate structures inside the eye.
Infections, injuries, inflammations, genetic conditions, surgical, and rarer conditions like tumours can damage the corneal and sclera. Damage to the cornea can render it opaque resulting in blindness. Damage to the sclera can threaten the physical integrity of the eyeball itself.

How can corneal and scleral diseases be treated? Read more…

Facilities at Darshan Eye Clinic for Corneal and Scleral Disease

  • Corneal Topography
  • Specular Microscopy
  • Corneal Pachymetry
  • Ocular Microbiology Lab


Glaucoma (high eye pressure) is a leading cause of blindness in the elderly, by damaging the optic nerve. When damage to the optic nerve occurs, blind areas develop in the field of vision, and usually go undetected until the optic nerve is significantly damaged. The most common form has no symptoms in its early stages. Glaucoma has therefore been nicknamed “the silent sight thief”. Worldwide, it is the second leading cause of blindness. Glaucoma affects one in two hundred people aged fifty and younger and one in ten over the age of eighty. Early detection is the key to preventing this damage. A regular eye pressure check is the best way to detect glaucoma.

What causes glaucoma and how can it be treated? Read more…

Facilities at Darshan Eye Clinic for Glaucoma

  • Applanation tonometry
  • Gonioscopy
  • Corneal Pachymetry
  • Humphrey Visual Field Analyzer
  • Optic Nerve Head Imaging
  • YAG Laser


Neuro-ophthalmology is a very specialized field of medicine incorporating the fields of ophthalmology and neurology. About 25% of the brain’s neurons are involved either directly or indirectly with vision. Many neurological conditions (including life-threatening diseases like tumours and aneurysms of the brain) often present first with eye symptoms. Many of the eye signs may be subtle and missed if not recognized. Besides specific facilities for neuro-ophthalmic evaluation, Darshan Eye Clinic has access to excellent facilities for Electrophysiological testing (like Visual Evoked Potentials) and neuroimaging (CT Scan and MRI) and cross-referral facilities to expert neurologists and neurosurgeons.

What are the signs of optic nerve disease. Read more…

Facilities at Darshan Eye Clinic for Neuro-ophthalmology

  • Ishihara Test Plates for Colour Vision
  • Humphrey Visual Field Analyzer

Ocular Surface Disorders

The conjunctiva is a protective covering of the eye and lines its entire surface from the margin of the cornea to the skin of the lids. It has many glands that secrete the watery and mucous part of the tears. It also contains the defense systems of the surface of the eye to fight infections. Injuries (such as chemical burns), infections and inflammations, allergies, and tumours can damage the conjunctiva. Some conditions can be vision-threatening.

Conjunctival disorders can be complex conditions with many modes of treatment. Read more…

Facilities at Darshan Eye Clinic for Ocular Surface Disorders

  • Special Staining Tests
  • Corneal Pachymetry
  • Dry Eye Evaluation

Squint and Child Eye Care

Any obstruction to vision at a young age can cause permanent damage to the visual system that cannot be corrected later. Since small children often may not notice such changes, it is very important that all children undergo a screening eye exam at an early age.

Refractive errors, misalignment of the eyes (squint), structural problems, retinal damage associated with premature births, and rarely a malignant tumor of the retina – retinoblastoma, are some of the conditions that can affect vision in children.

How can squints and “lazy eyes” be treated? ead more about the Child’s Eye…

Facilities at Darshan Eye Clinic for Child Vision Examination

  • Ishihara test Plates for Colour Vision
  • Prism Bars for Squint Assessment
  • Titmus Fly test for Stereopsis
  • Synoptophore

Retinal Health

The retina is a delicate, extremely complex light-sensitive “screen” that lines the inner wall of the back of the eye. The vitreous is a jelly-like mass that fills up the back of the eye and has shock absorbing and nutritional functions. Retinal degenerations and holes that can lead to detachment of the retina, damage due to diabetes mellitus and high blood pressure, and age-related macular degeneration are some of the more common retinal conditions that can damage sight.

What are the symptoms of retinal disease? Read more…

Facilities at Darshan Eye Clinic for Retinal and Vitreous Diseases

  • Indirect ophthalmoscopy
  • B-Scan Ultrasonography
  • Special lenses for retina and vitreous evaluation
  • Digital Fundus photography and Fluorescein Angiography
  • Argon Laser Treatment
  • Laser Indirect Ophthalmoscope
  • Cryotherapy

Ocular Inflammations

Think of the eye as a hollow, fluid-filled, 3-layered ball – the outer layer is the sclera, a tough coat, the innermost is the retina, the thin light-gathering layer, and the middle layer is the uvea. The uvea is made up of the iris, ciliary body and choroid. Intraocular inflammation, also called uveitis, affects this layer.

Why is uveitis such a serious problem? Read more…

Facilities at Darshan Eye Clinic for Ocular Inflammations

  • B-Scan Ultrasonography
  • Digital Fundus photography and Fluorescein Angiography

External Eye, and Orbital Diseases

The lacrimal system secretes the tears that keep our eyes wet and optically clear. The eyelids also contribute to the tear film besides physically protecting the eyes. The orbit is the bony “socket” that contains the eyeball and associated structures. It protects the sensitive structures required for normal vision, especially the eye itself. It also anchors the extraocular muscles that move our eyes.

What can go wrong with the lids and lacrimal system? Read more…

What are the symptoms of orbital disease? Read more…

cilities at Darshan Eye Clinic for External Eye and Orbital Disease

  • Hertel’s Exophthalmometer
  • Dry Eye Evaluation

Computer Vision Syndrome Clinic

Most people who work constantly with computers tend to have some or all of the following symptoms – eyestrain, eye fatigue, dry eyes, light sensitivity, blurred vision, loss of focus, double vision, headaches, and neck and shoulder pains. This symptom complex has been termed the computer vision syndrome (CVS).

What causes Computer Vision Syndrome? Read more…

Facilities at Darshan Eye Clinic for Computer Vision Syndrome

  • Autorefractokeratometer
  • Dry Eye Evaluation
  • Flipper test for Accommodative Facility
  • Synoptophore
  • Ergonomic Assessment and Counselling

Spectacles and Contact Lenses

Advances in spectacles lens materials and designs over the years now allow improved visual quality. Besides being used for correcting refractive errors and for cosmetic reasons, contact lenses are used as treatment modalities in corneal and external eye disease.

What are the recent advances in spectacles and contact lenses? Read more…

Facilities at Darshan Eye Clinic for Spectacles and Contact Lenses

  • Contact Lens Clinic
  • Darshan Optical Services

Ancillary Services

Darshan Eye Clinic has been conceived as a one-stop-shop for eye health. Ancillary facilities allow our patients to complete their eye examination, relevant investigations, and medical treatment at the clinic itself.

  • Optical Services
  • Pharmacy
  • Ocular Microbiology Laboratory


Types of contact lenses:

  • soft lens
  • semi soft (RG P)
  • prosthetic lens
  • bandage lens
  • cosmetic
  • X chrome lens

Soft lens:

It comprises of 2-hydroxyethylmethacrylate (HEMA) molecules which absorbs water content (hydrophilic). These lenses can be used either as daily wear lens or disposable lens according to requirement of the user. Disposable lenses are thinner than regular lenses, but give more comfort

Soft lenses are preferable for:

  • Cylindrical correction less than 1 Diopter, Myopes (minus power), Hyperopes (plus power), special toric lens for power up to 2.25 Diopter of cylindrical correction
  •  More comfort
  •  Sports persons
  •  A healthy Cornea (the black portion of the eye) without any abnormalities
  •  Stable power

Semi soft lens:

It comprises of 2-hydroxyethylmethacrylate (HEMA) molecules which absorbs water content (hydrophilic). These lenses can be used either as daily wear lens or disposable lens according to requirement of the user. Disposable lenses are thinner than regular lenses, but give more comfort

Semi soft lens are preferable for:

  • Cylindrical power more than 1 Diopter up to 4 Diopter, high myopes and hyperopes
  •   corneal abnormalities leaving scars due to infections
  • Aphakia (absence of lens due to injury, infections etc)
  • Keratoconus – steepening and variation in curvature of cornea, which ends in frequent change of glasses

Prosthetic lens:

It is a soft lens made with colours to give false appearance, to match the normal eye. It can also be provided with powers.

Prosthetic lens are suited for:

  • White opacities in the cornea (black portion of the eye)
  • Matching the blind eye (this is applicable only when the other eye is either damaged or having any ocular defect

X –chrome lens:

It is a red colored soft lens which is used to improve the contrast in red deficient people

Bandage contact lens:

It is a transparent soft lens without any power to improve the wound healing process of the cornea with the help of suitable medications. Medications may be applied with the bandage lens on the eye.

Cosmetic lens:

It is a soft lens made with different colours to match other cosmetic features of the user’s body

Do’s and Don’ts:

  • Always wash hands before handling lenses
  • It is advisable to follow the instruction given by the practitioner for inserting and removing lenses
  • Clean and rinse the lenses every time, on removal
  • Disinfect them every day by soaking them in to the lens cleaning solution
  • Always store the lens in solution, whenever the lenses are not in use
  • The soaking solution must be changed every night
  • The case must be cleaned regularly with warm water at least twice in a week
  • It is advisable to apply cosmetics after inserting lens, cosmetics better to be used in a limited manner
  • Ensure nails are short and clean
  • For deposit removal enzyme tablets may be used on consent of the practitioner
  • It is a must that the contact lens is removed before sleeping
  • Wear time of 12 hrs to 14hrs is the permissible duration per day
  • Eye medication are not to be applied while the lenses are being worn


What is a fundus camera?

Fundus camera is an instrument which is used to take the picture of the interior part of the eye called the retina. The fundus camera is also used to take picture after injecting a dye, a method called fundus fluorescein angiography

What is a fundus photo?

The pictures of the optic nerve, vitreous changes, macula, retina and its blood vessels are taken.  The photographs are used for comparison, documentation, and sometimes to diagnose certain eye conditions.

Because fundus photography is a highly specialized form of medical imaging, it can’t be done with an ordinary camera.  It requires a customized camera that is mounted to a microscope with intricate lenses and mirrors.  These high-powered lenses are designed so the photographer can visualize the back of the eye by focusing light through the cornea, pupil and lens.

What is the procedure of doing fundus photography?

The pupil is first dilated with drops. Otherwise, it would automatically constrict from the bright light of the camera flash. The patient is asked to stare at a fixation device so the eyes are still.  While the photographer is taking the pictures, the patient will see a series of bright flashes.  The entire process usually takes approximately five to ten minutes.


Hertel’s exophthalmometer

What is exophthalmometer?

It is an instrument with an adjustable scale and holding mirror on the sides.

What does it do?

It has two mirror on the sides which reflects the image of the eye ball on the scale from which the protrusion of the eye ball is measured axially in millimeters

When is it indicated?

The test is indicated in case of prominent eye balls in disease like thyroid opthalmopathy, orbital tumour, ocular injury, neurological diseases and muscle thickening


It is used in refraction to decide on prescribing cylindrical power in the glass with appropriate axis (direction), to find out whether there is any cylindrical power to be added. The use of this instrument greatly increases the accuracy of refractive power testing for the eye.


What is a pachymetry?

A pachymetry test is a simple, quick, painless test to measure the thickness of your cornea. It is generally performed in people with corneal diseases and for those who are interested in undergoing corneal refractive surgery or LASIK.

With this measurement, your doctor can better understand your IOP reading, and develop a treatment plan in patients who is suspected to have glaucoma. The procedure takes only about a minute to measure both eyes.

Who is at Risk for Glaucoma?

People at high risk for glaucoma include people with increased eye pressure; everyone over the age of 60; people of African descent over the age of 40; and people who have a family history of glaucoma.

What does the recent study say about glaucoma and corneal thickness?
Recent discoveries about the cornea, the clear part of the eye’s protective covering, are showing that corneal thickness is an important factor in accurately diagnosing eye pressure. In response to these findings, the Glaucoma Research Foundation has put together this brief guide to help you understand how your corneal thickness affects your risk for glaucoma, and what you can do to make sure your diagnosis is accurate.

Why is Corneal Thickness Important?

Corneal thickness is important because it can mask an accurate reading of eye pressure, causing doctors to treat you for a condition that may not really exist or to treat you unnecessarily when are normal. Actual IOP may be underestimated in patients with thinner CCT (central corneal thickness), and overestimated in patients with thicker CCT. This may be important to your diagnosis; some people originally diagnosed with normal tension glaucoma may in fact be more accurately treated as having regular glaucoma; others diagnosed with ocular hypertension may be better treated as normal based on accurate CCT measurement. In light of this discovery, it is important to have your eyes checked regularly and to make sure your doctor takes your CCT into account for diagnosis.


What is a specular microscope?

It is an instrument which helps to examine the inner most layer of the cornea called the endothelium. It helps to evaluate the number of cells, size and shape of the cells in the layer.

How is it measured?

An automated, non-contact measurement of the endothelium is obtained in a few seconds using an advanced state-of-the-art instrument. The computerized analysis will printout the vital statistics of the corneal endothelium within seconds of the measurement being made. This instrument is vital for the proper management of corneal diseases.


What is A Scan?

It is a method of measuring the axial length of the eye ball using ultrasound. This test is done to measure the axial length of the eye ball (i.e.) the distance from the front surface of the eye ball (cornea) to the back surface of the eye ball (retina).

When it is recommended?

This test is done when there is any suspicion of reduced or increased eye ball size like in myopia in one eye and hyperopia in other eye, small eye ball since birth, protrusion of one eye and is always performed before cataract surgery to calculate the power of the lens.

How is it performed?

It is done using a drop of local anesthetic, and the patient has to focus at one point. It is a painless test and takes about 2 to 3 minutes. The ray of light is allowed to pas through the eye from the front surface to the back surface and it is measured in millimeters. The waves are projected on the touch screen and the print out can also be taken.


What is a keratometer?

It is an instrument which helps the doctors to assess the surface regularity of the cornea.

When is it performed?

Keratometry is done to confirm the cylindrical power as an additional test in correcting the eye power while refraction. It will also be done in fitting the contact lens to suit the right base curve. The other important usage is while calculating the intraocular lens power along with the digital biometry.


What is a biometry?

Biometry is a way of measurement of the calculating the power of the intraocular lens that has to be kept after performing the cataract surgery.

What are the tests involved?

The Keratometry is performed first to get the surface curvature of the cornea along the horizontal and the vertical meridian. Then a-scan is measured to get the axial length of the eye ball. These two reading are combined to find the values using a formula.

What does the use of digital biometry?

Digital biometry makes the calculation easier and error free in a short time. The test is done in five minutes and the reports can be prepared in five minutes. The report can also be printed from the machine which reduces the time for copying.


What is an autorefractometer?

This is an automatic computerized instrument that helps to measure the refractive error of the eye and display it on the screen.

What is the role of auto refractokeratometer?

This is also an automatic instrument with multi purpose usage. This is user friendly. It helps the doctor to measure the refractive error of the eye and also the corneal meridional power that is generally called astigmatism. The usage is similar to the keratometer in fitting contact lenses as well.

What is the speciality of this instrument?

The test can be performed even in small children and old patients since it has got a motorized table. This instrument also has got an auto focus capacity so that once the eye is selected it will focus automatically and the measurement takes only a few seconds. It has got the printer attached with it which gives the printed document with in few seconds after the test is done.

Computer vision syndrome

It is a combination of eye related symptoms like eye strain eye fatigue, dry eyes, light sensitivity, blurred vision, focusing difficulty, double vision, head aches, neck and shoulder pain – together called computer vision syndrome.

Symptoms and Recommendations:

1. Blurred vision on seeing the computer – if there is any refractive correction please wear the glasses regularly
2. Eye strain at the end of the day – please give adequate breaks every 20 min and try to look at 20 feet for about 20 secs
3. Dry eyes – it may be due to inadequate blinking. Try to blink at least 15 times in a minute and apply artificial tears as per the doctor’s instruction
4. Double vision – The problem may be due to the poor fusing mechanism or reduced focusing ability of the eye muscles. Please consult the doctor to see if the following exercises are required
a) Pencil push up
b) Accommodative rock
c) Cat card
d)  Accommodative flippers
5. Postural pain – please follow the recommended ergonomics to avoid the problems


  1. the monitor should be kept away from the eyes by at least one arm distance
  2. viewing angle should be 10 to 15  degrees below the straight ahead eye position
  3. the lighting should be adequate without producing reflections either on the screen or to the eyes
  4. please keep the keyboard tabs flat, rising the tab can make wrist angle while typing which can produce wrist pain
  5. keep the shoulders relaxed and not raised to avoid shoulder pain.
  6. keep the neck and head straight and make the eye angle down to see the monitor. The table height or the computer height can be adjusted.
  7. the legs should make an obtuse angle or atleast an right angle to the floor to avoid thigh and joint pain
  8. the sitting chair can be made with aback support; if not a small pillow can be used to support the spinal cord.
  9. try to sit erect and avoid any forward bend of the back bone which makes the vertebral column relaxed.
  10. letters to  be typed can be placed in the letter holder to avoid any down, up head movements.
  11. maintain proper font size, contrast, font. Black and white contrast is better and safe.

Darshan eye clinic

Why eye examination?

The eye examination helps us to detect the conditions like glaucoma, hidden hyperopic correction, intermittent squint, Colour deficiency, retinal weakness (degenerations), muscle weakness (accommodative eye muscle problems), which are rarely noticed by people on their own, apart from usual spectacle corrections and treatment for other diseases of the eye.

What does the optometrist do?

The optometrist does the following procedures before the doctors see you.

  1. history- information about the problems of eyes , general health and the medications that are being used
  2. to check the glass power is appropriate
  3. to check for any eye muscle problems associated with focusing difficulty, head ache, eye strain, double vision, glare and distortions
  4. to check eye pressure

These have been done as a routine and the eyes will be dilated with eye drops for the doctor to see.

Other specialties

  1. Contact Lensesconsultation will be done and the trial lens will be put to see the comfort the lens and then the final lenses will be ordered
  2. Orthopticsa special procedure to investigate eye muscle problem
  3. Synoptophoreexercise for eye muscles including children with squinting.
  4. Humphrey Visual Fields – to detect the side vision loss if recommended by the doctors
  5. Topographyto investigate the surface irregularity of the black portion of the eye(the cornea) , especially for laser treatment for correcting glass power
  6. Pachymetryto find the thickness of the black portion for determining the procedure for the laser treatment for correcting the glass power.
  7. Digital Biometry Reader –  to find the correct power of intra ocular lens that has been put after the removal of cataract
  8. Low vision aids people with less vision of 3M in the better eye can be given some specialized glasses in case of night blindness, retinal diseases to manage their day to day activities without much difficulty.

To learn more about each, please click the button DETAILS in each section.


What is a visual field?

Visual field refers to the field of view or the extent of visibility of things around us while seeing straight. The normal human visual field extends to approximately 60 degrees nasally (toward the nose, or inward) in each eye, to 100 degrees temporally (away from the nose, or outwards), and approximately 60 degrees above and 75 below the horizontal meridian

How is the visual field measured?

The visual field is measured by perimetry. This may be kinetic, where points of light are moved inwards until the observer sees them, or static, where points of light are flashed onto a white screen and the observer is asked to press a button if he or she sees it. The most common perimeter used is the automated Humphrey Field Analyzer.

Why it is done?

This test is done to check the peripheral (side) vision which helps people in mobility. The test is recommended in a number of cases such as increased eye pressure (glaucoma), retinal nerve disorders diabetic retinopathy, retinitis pigmentosa), and neurological related eye problems (optic neuropathy, disc swelling)

How is the test done with Humphrey Field Analyzer?

Targets of different intensity is shown as lights at different points inside the screen and the patients are asked to respond if they appreciate the targets by pressing the button. The responses are matched with the normals of the same age to give a grey scale plotted map.

It is a straightforward, painless test. There is no physical contact with the eye in the test. It does not involve eye drops

The results are obtained immediately as the system is computerized and provides printouts at the conclusion of the test.

Instrument list

Optometrist room

  1. Lensometer
  2. Projector
  3. Retinoscopy
  4. Jackson’s cross cylinder
  5. Colour vision chart
  6. Stereopsis chart
  7. Amsler chart
  8. Slit lamp
  9. Auto refractometer
  10. Contact lenses
  11. RAF ruler
  12. Maddox wing
  13. Prism bar
  14. Humphrey visual fields
  15. Synoptophore
  16. Manual keratometer
  17. A scan/ Digital Biometry Reader
  18. Topography
  19. Pachymeter

Consultant room

  1. Indirect Ophthalmoscope
  2. Direct Ophthalmoscope
  3. 20 D , 90 D , 78 D
  4. Gonioscope – Zeiss four mirror, Goldman three mirror gonio lens
  5. Exopthalmometer
  6. B-scan
  7. Fundus Fluorescein Angiography
  8. Retinal laser
  9. Yag laser
  10. Yag capsulotomy lens
  11. Argon laser diode lens
  12. Iridectomy lens


Definition: LOW VISION IS NOT NO VISION!” The definition of legal blindness is a visual acuity of 20/200 in the best eye with best correction or a visual field of 20 degrees or less.

What is Low Vision?

Low vision is a visual impairment severe enough to interfere with performance of daily activities, yet allowing some usable vision.

What Causes Low Vision?

There are many different conditions that can cause low vision, including:

  • Macular Degeneration
  • Diabetic Retinopathy
  • Cataracts
  • Glaucoma

People with low vision may have difficulty with daily living activities such as:

  • Dressing
  • Cooking
  • Use of dials on the microwave, telephone
  • Reading
  • Writing

Therapy can help you regain and maintain independence in your life.

What to Expect

  • To assess your visual impairments
  • Train you in the use of adaptive equipment
  • Educate you about techniques that compensate for low vision
  • Help you to return to functional and independent living


Orthoptics, meaning “straight eyes,” is one of the medical sciences specializing in eye care. Orthoptics is the study of the development of vision, depth perception and the ability to use the eyes together, eye alignment, eye movements, and eye coordination. The orthoptist’s particular area of expertise is the evaluation and management of children and adults with “crossed” eyes, “lazy” eye, double vision, and other eye coordination problems.

Orthoptic evaluation involves the measurement of the muscle action according to the age requirements, including any deviation of the eye


Stereopsis The ability to perceive the depth perception
Accommodation The ability of the eye to focus for distance and near by stimulation and relaxation of the muscles.
Amplitude The reading materials kept at normal working conditions converted into power (Diopter)
Convergence The ability of the eye to work or focus by converging (moving the eye ball inwards)

Orthoptics involves the measurement of accommodation, amplitude and convergence.

Facilities at Drashan Eye Clinic for an Orthoptic Evaluation:

The optometrist at Darshan is equipped with all equipments needed for a complete orthoptic eye exam

    1. Titmus fly chart for measuring Stereopsis and ishihara for colour vision testing


    2. Flippers for measuring accommodation and vergence functions
    3. Maddox rod and Worth four dot for the measurement of double vision (diplopia)
    4. Prism bar for measurement of squinting of the eye and convergence
      Text Box:
    5. Synoptophore for measuring the fusional range, convergence, squinting, for giving exercise to lazy eye.

    6. Amsler chart for documentation of distortions in disease like diabetic retinopathy and  other retinal problems

Darshan eye clinic Refractive Errors

What is an eye examination?

A complete eye exam starts with a detailed history of eye and general health problems, problems in other family members, and current medication history. The power of the spectacles being used is then checked and visual acuity is recorded with the correction being used – glasses or contact lenses. If the vision is found to be less than optimal refraction is performed and recorded to provide the optimal correction. The movements of the eye and the papillary reactions are then tested. A slit-lamp examination is performed to allow a study of the structures of the eye under adequate illumination and magnification, after which the intraocular pressure is measured. The pupils are then dilated to examine the retina and optic nerve in detail. All of these can be performed quickly and effectively by a well trained optometrist.

How long does an eye examination take?

This examination routine usually takes 10 to 15 minutes and dilatation of the pupils another 30 minutes. After dilatation, the ophthalmologist will complete the retinal evaluation and discuss the findings with you. The cause of problems if any and the requisite treatment measures are then discussed. The entire process should take an hour from start to finish.

When is an eye examination required?

Obviously, any change in vision or ocular comfort warrants an immediate eye exam, as does an injury to the eye. Other indications for an eye exam are abnormal head postures or squinting eyes in children, or a tendency to hold objects very close to the eyes. Even in asymptomatic children, a routine screening evaluation at the time of schooling can help detect conditions like a ‘lazy’ eye, small degrees of squint, color deficiency, and loss of 3-dimensional perception. In adults, a routine evaluation at the age of 40 years, allows the detection and correction of presbyopia, and monitors the intraocular pressure to ensure that glaucoma does not exist. Periodic eye exams after the age of 50 years at yearly intervals, or when systemic conditions like hypertension or diabetes are detected are necessary.

Are specialized tests done routinely during an eye exam?

Apart from the routine procedures described above, if problems are detected, then your ophthalmologist may decide to order special investigations and procedures, after discussing their need with you. These could include investigational procedures like visual field examination and photography of the optic nerve for glaucoma, corneal topography and pachymetry to determine your suitability for LASIK, ocular ultrasonography for evaluating the posterior segment of the eye, fundus fluorescein angiography for retinal disease, keratometry and eyeball length measurement for determining the power of the intraocular lens required during cataract surgery, or laser procedures using the Nd:YAG or Argon lasers for other eye problems.

Do these specialized tests and procedures require another visit or travel to another facility?

No. All of these can be performed during the primary visit, and can be done at Darshan Eye Clinic itself – as the center is fully equipped for total vision care.

How do I decide what refractive correction is appropriate for me?

A variety of refractive options are now available that will fulfill the needs of all patients. It would be best to discuss your needs and requirements with your ophthalmologist – after a detailed evaluation of your eyes, he would help you decide the most suitable option for your eyes.

What are the different types of spectacles and what are their advantages?

In general spectacles form a safe and effective form of correction for most visual needs. A variety of options exist for this – both in the form of frames which can be light and hardy – shell frames; rimless and semi-rimless for a more stylish appearance; metal frames in various colors and designs; and designer wear for the fashionable. Lenses for refractive correction can be single vision – and with the advent of the high refractive index lenses, these can be made quite thin, both in glass and plastic to allow an acceptable cosmetic appearance.

hat are ‘progressive’ lenses and when are they indicated?

For older persons, who need bifocal corrections, the advent of the progressive lenses has proved a boon, and not only are these cosmetically better in appearance, they also provide enhanced functionality. The absence of a separately powered inferior segment – as in the traditional bifocal – allows a seamless change in power from that for distance vision, to that for near vision – and this also incorporates the effective correction for intermediate distance – which is especially useful for those who work with computers for their daily activities. These glasses are also more suitable for those who spend time outdoors and indoors as the lack of a bifocal segment enables them to adjust easily to all activities.

Where can I get these spectacles made?

Darshan eye clinic has an in-house optical service for the needs of its patients. Spectacle frames and a variety of lens choices are available to ensure that patients have their needs met in a scientific and cost effective manner.

When should I consider contact lenses?

If glasses are considered unacceptable for cosmetic or occupational or recreational needs, then contact lenses can help. A contact lens is a transparent lens which is positioned on the center of the black portion of the eye (the cornea). Contact lenses are basically of two types – soft and rigid. Soft lenses are usually preferred as they provide greater wearing comfort. For ‘simple’ myopic and hyperopic errors, without much astigmatism, regular soft lenses are adequate. These are now available as ‘disposable’ lenses – usually changed once in 2 weeks, once a month, or once in 3 or 6 months. The advantage of disposable lenses is that the protein buildup that occurs with long-term use, can be avoided. If however, the eye has a significant amount of astigmatism, then the regular soft lens designs will not provide clear vision. To correct this astigmatism, a special type of soft lens, called the toric lens must be used. In general, these lenses are more costly than the regular lenses, although these are also now available in disposable designs. If soft lens use results in an allergic condition in the eye, as happens rarely, then the patient may need to consider the use of rigid lenses, usually the semisoft design. These lenses are made of a different material compared to soft lenses, and can often be used when allergy develops to soft lenses. Another important indication for the use of these semisoft lenses is when the cornea is abnormal. This may be due to the presence of corneal scarring from previous injury or infection, or due to a loss of the regular shape seen in some genetic conditions – the commonest of which is keratoconus. In other eyes that have been fitted previously with very tight soft lenses, the corneal periphery called the limbus and the delicate cells on the back of the cornea – called the endothelium, may suffer from the lack of a proper oxygen supply and in these eyes, the use of a semisoft lens (also called a rigid gas permeable lens or RGP lens) is a better design, as it promotes a better oxygen supply to the cornea and limits further corneal damage.

What does the contact lens fitting process involve?

The optometrist will measure the corneal curvature in your eyes using an instrument called a keratometer. Using these values as a guide, an appropriate ‘trail lens’ from a set available in the clinic is fitted to your eye. The fit of the lens on the eye is assessed, and if required modified. Vision is tested and the correct power required for the lens is determined. In the case of regular soft contact lenses – they can be directly made available from the inventory available at Darshan Eye Clinic. For toric soft contact lenses and for the RGP lens, the appropriate lens is ordered from the laboratory and delivered to the patient in 24 to 72 hours. The Contact Lens Clinic will also provide the patient with detailed instructions on the use and care of the lens and the necessary solutions that are needed to maintain the contact lens. In order to help fit patients with distorted corneas, the clinic has a special set of contact lenses that have allowed patients with difficult problems – due to shape distortion or after corneal surgery, to be fitted with comfortable lenses that allow clear vision.

Are there other types of ‘special’ contact lenses?

Yes. Apart from the lenses described above which are for providing the patient with good vision, there are other types of lenses as well.

Prosthetic lens

These are soft lenses which are used to mask corneal opacities in unsightly blind eyes. The colors help match the color of the fellow normal eye and the central black zone provides an appearance of normality in a scarred eye.

Cosmetic lens

These are soft lenses that are colored, but have a clear central zone. These are used for cosmetic purposes, when the user desires to change the color of the eye. The clear center is used to allow good vision in these sighted eyes. They can also be made to incorporate a refractive power in the central zone in patient who also have refractive errors.

X –chrome lens

This is a soft lens which is colored orange and helps improve contrast in some people with a red color deficiency.

Bandage contact lens

In certain disorders that disrupt the integrity of the surface of the cornea, the use of a special high water content lens performs the function of a bandage on the eye, allowing the damaged epithelium to heal. This lens can often be left in place for a month at a time to protect the cornea.

What are the Do’s and Don’ts of contact lens wear?

      • Always wash hands before handling lenses
      • It is advisable to follow the instruction given by the practitioner for inserting and removing lenses
      • Clean and rinse the lenses every time, on removal
      • Disinfect them every day by soaking them in to the lens cleaning solution
      • Always store the lens in solution, whenever the lenses are not in use
      • The soaking solution must be changed every night
      • The case must be cleaned regularly with warm water at least twice in a week
      • It is advisable to apply cosmetics after inserting lens, cosmetics better to be used in a limited manner
      • Ensure nails are short and clean
      • For deposit removal enzyme tablets may be used on consent of the practitioner
      • It is a must that the contact lens is removed before sleeping
      • Wear time of 12 hrs to 14hrs is the permissible duration per day
      • Eye medication are not to be applied while the lenses are being worn

What is ‘refractive surgery’?

When patients with refractive errors want to have good unaided vision without the use of spectacles or contact lenses, then surgical correction of the error is an option. Currently, the most common procedure to achieve this goal is termed LASIK – and the acronym stands for Laser Assisted In Situ Keratomileusis. It refers to the use of the excimer laser to reshape the cornea after a corneal flap is created using an instrument called a microkeratome.

In patients with corneas that are thinner than normal, the use of a corneal flap can prove dangerous, and in these patients, the procedure is performed after removing the corneal epithelium alone – and is termed LASEK – Laser Assisted Subepithelial Keratomileusis.


What is a corneal topographer?

A corneal topographer shines light onto the surface of the eye, then measures the reflected light to create a map of the cornea’s curvature as well as any irregularities. The color map uses blue and green to represent flatter areas of the cornea, while red and orange represent steeper areas of the corneal curvature.

When is the test indicated?

The map is used for evaluations related to refractive surgery, contact lens fitting and corneal disease management. It is especially useful for measuring astigmatism. The test is recommended in people who are willing to do laser correction to avoid glasses, in case with suspicious corneal problems like pellucid marginal degeneration, Keratoconus.

What is the advantage of this instrument?

This being an automated one takes only few seconds to photograph the eye and gives the result immediately in the monitor. The reports of each person can be stored in the software and a copy of the report can be printed from this itself. This software helps the doctor to compare the results before and after the treatment either with lasik or with contact lens use.


The mapping shows the changes in the curvature in the front surface of the cornea between each meridian