Corneal Refractive Therapy (CRT) Lens are special type of lens which correct the problem with vision and helps to have normal vision without actually wearing the lens.Unlike contact lens and glasses, you have to put it on when you go to sleep and take it off when you wake up!.Then for the next 70 hours or so, you will have a clear vision like any normal individual.At present this lens is successful only with short sighted people or people with myopia.And those having farsightedness or those who can see far off objects clearly and but not ones nearby cannot use this lens.

How it works?

This lens actually reshapes the cornea during sleep.We know that cornea is the  part of eye that bend the light ray entering the eye and thus help to focus the image on the retina.In short sighted people (myopia), this image is formed in front of retina and thus vision is blurred.When such a person use glasses or contact lens, it help the image to be focused on the retina.In this case, when the person use CRT lens, it will reshape the cornea and change its light bending qualities and thus image will be formed in the retina like any normal eye.

The CRT lens is very similar in appearance to a standard contact lens.After using it the vision is also said to very clear.But the main disadvantage is that it is only suitable or designed for people with low to moderate myopia (nearsightedness upto - 6.00 diopters), with or without astigmatism (up to - 1.75 diopters).Also this lens cannot be used by those who use bifocal glasses.

At present this type of lens is used in western countries.In India it is undergoing various testing and we can expect to buy such lens within 6 months according to the doctors in All India Institute of Medical Sciences.