What can Zyoptix correct?
Explaining the differences between the normal eye and vision errors such as myopia will help you to understand what laser eye treatment and Zyoptix are designed to do.
Your vision can be either normal, myopic (near- or short-sighted), hyperopic (far-sighted) or astigmatic (complex). Obviously, normal eyes do not need any correction - except at middle age (40-50), when they become presbyopic (old age vision) and 'reading glasses' are needed to see small close-up objects. Laser eye surgery can be applied to correct near-sight, far-sight and astigmatism. However, at this point in time, Zyoptix cannot be used to correct far-sight.
The eye is nature's camera. The light that comes into the eye passes through the curved surfaces of the cornea and lens, which bends the light to focus on the retina.
The curvature of the cornea is very important, since it has a major influence on your type of vision and offers an ideal surface to correct vision. Laser eye treatment works by changing the shape of the cornea to correct or re-align the focus.
Myopia/Near (short) - sight:
This is a very common vision problem and is often inherited. Myopic people can see very well close-up, but distant images are blurred. This is caused by the curve of the cornea being too 'steep' or because the eyeball is too long. Laser surgery corrects myopia by flattening the curve of the cornea, pushing the focal point back onto the retina.
Astigmatism
Astigmatism is very common. The cornea is shaped more like a rugby ball than the normal round cornea and has 2 different curvatures (one rounder than the other). This simply means that, instead of one curvature (with standard short or near-sight), there are two curvatures that need to be corrected, at the same time and during the same treatment, to make sure that there is only one focal point falling on the retina.
What laser eye treatment does NOT correct
Presbyopia: In middle age, everyone's eyes - whether normal, myopic or anything else, become presbyopic. This means that in addition to your distance correction (if you have one) you will need glasses for close-up activities.
Neither standard LASIK nor Zyoptix can correct presbyopia. However, people who have presbyopia will benefit from having their distance vision corrected, and will thus only need glasses for close-up activities.