Clear vision in the normal eye is due to light rays falling on the eye and passing through the cornea, pupil and lens and focusing the image on the retina.
When the eye is too long, light focuses in front of the retina causing myopia (Short Sight). When the eye is too short, light rays focus behind the retina causing hyperopia (long sight). When the cornea is shaped like the back of a spoon, light focuses on more than one point and a blurred image is formed on the retina and this is known as astigmatism (Cylindrical power) and is often associated with short sight or long sight.
Spectacles – most common solution with easy maintenance and low cost.
Contact lenses – popular alternative to spectacles.
Permanent surgical corrections
Refractive surgery is the term used to describe surgical procedures that correct common vision problems (nearsightedness, farsightedness, astigmatism and presbyopia) to reduce your dependence on prescription eyeglasses and/or contact lenses.
LASIK (LAY-sik) is the most popular refractive surgery performed.
LASIK is a surgical procedure that uses a laser to correct nearsightedness, farsightedness, and/or astigmatism. In LASIK, a thin flap in the cornea is created using either a microkeratome blade or a femtosecond laser. The surgeon folds back the flap, then removes some corneal tissue underneath using an excimer laser.
ICL ( Implantable collamer lens):
Phakic IOLs (intraocular lenses) are an alternative to LASIK and PRK eye surgery for correcting moderate to severe myopia (nearsightedness), and in some cases produce better and more predictable vision outcomes than laser refractive surgery.
Phakic IOLs are clear implantable lenses that are surgically placed just behind the iris, without removing your natural lens. Phakic lenses enable light to focus properly on the retina for clearer vision without corrective eyewear.
Implantable lenses function like contact lenses to correct nearsightedness. The difference is that phakic IOLs work from within your eye instead of sitting on the surface of your eye. Also, phakic IOLs offer a permanent correction of myopia, Unlike contact lenses, you can't feel a phakic intraocular lens in your eye and, apart from regular eye exams, phakic IOLs typically do not require any maintenance.
Eligibilty for surgical corrections – should be of minimum 18 years of age with stable spectacle power for 1 year and with no history of other eye diseases.