Normally light entering the eye is focused on to the retina by the cornea and the lens producing a sharp and clear image. Disparity between focusing power and length of the eyeball results in defocus and is called a refractive error. In myopia the eyeball is too long and in hyperopia the eyeball is too short. The spectacles and contact lenses correct this defocus and allow clear and crisp vision Astigmatism or cylindrical power is a type of error in which one surface of the cornea is more curved than the other causing an elliptical defocus. It is corrected by cylindrical lens spectacles or toric contact lenses. The greater the power of spectacles the greater the defocus without glasses and hence greater dependency on the glasses While Spectacles and contact lenses offer effective correction they have their limitations i.e. need to be put on and taken off daily and cared for. They are a good option during the growing years when the spectacle power constantly changes and permanent solutions are not advisable Once the spectacle power has stabilized, permanent alternatives to spectacles/contact lenses are considered

PRK/ LASIK/ LASEK are all forms of Laser vision correction which allow clear vision without spectacles/lenses in most cases and spectacle independence in all individuals who are suitable candidates for it. This allows a person broader career opportunities and hindrance free outdoor activities like swimming, trekking, football/ tennis. After laser, even small things like driving in the rain/stepping out of an AC room without the annoyance of your spectacles fogging give great satisfaction.

Individuals over the age of 18 years with a stable spectacle power for a year.

Those with spectacle number of between -8, to +5 and cylindrical power of up to 4 (those with higher powers need to be assessed individually for suitability).

Those with no retinal or other eye disease.

This is a short procedure in which the shape of the front of the eye (cornea) is altered to change its focusing power and hence eliminate/minimize the need for glasses While these procedures have excellent results, a detailed evaluation needs to be done before the procedure is planned to ensure optimum results.

Pre procedure evaluation:All individuals wearing contact lenses must stop wearing them for a week before evaluation to avoid wrong readings due to lens warpage. Tests include:

Verification of spectacle power(with and before instilling drops)

Measurement of corneal power(keratometry)

Mapping of corneal surface( topography)

Measurement of corneal thickness(pachymetry)

Measurement of aberrations if any(aberrometry)

Examination of the eye for dryness, any scars/opacities, etc (slit lamp biomicroscopy).

Measurement of eye pressure (tonometry).

Examination of the retina (fundoscopy).

After evaluation a detailed counseling is done to ensure realistic expectations thus maximizing outcomes. The laser procedure with the current newer generation machines is very predictable and accurate. The tracking systems prevent eccentric (off axis) treatment. With all the data obtained in the evaluation it is possible to customize the procedure to the individual eye affording better quality vision after the procedure. While the actual laser procedure is the same there are some basic differences between LASIK and PRK. In LASIK the treatment is done under a flap while in PRK it is done on the surface of the cornea PRK gives equally good results for lower powers as LASIK. However LASIK is virtually pain free and allows quicker recovery with a much lower risk of haze and regression.

Post Procedure:

Done as a day procedure

Follow up: next day, day 3, day 7, 1 month.

Rest to the eyes for 3-4 days-then resume computer/near work(near focusing slightly difficult for a week to 10 days)

Frequent instillation of drops for a couple of weeks

Prolonged use of lubricating drops(4-6 months)

Avoid strenuous/contact sports for 1 month.

No swimming/water sports for 2 months.

No eye make up/cosmetics for 1 month.

UV protection sunglasses when out doors for 4-6 months.

his procedure is an option for people who have high spectacle power and thin corneas and are not eligible for laser correction. While not suitable for everyone this procedure widens the scope of correction for spectacle elimination

Preoperative testing includes

Detailed eye examination and confirmation of exact spectacle power

Biometry to decide power of lens to be inplanted

ASOCT to confirm the width of the anterior part of the eye and ensure eligibility

Laser iridotomy is done. Unlike laser vision correction the procedure is done for one eye at a time.