If you are not already aware of all the possible refractive errors that one can have in their cornea and lens, then you should learn a bit more about them. Most likely when you have gone to your opthomologist they have been discussing myopia, hyperopia or maybe even astigmatism when discussing your vision. These three are simply normal issues that people have with their cornea and lens, in relation to their eyeball.

To make things really simple I will post two pictures here that will describe the whole thing in detail.

First of all there is the hyperopia. You can easily see that the eye is simply too short for the beam of light to be correctly focused on the retina, or in some cases the refractive power of the lens and cornea combined simply isn’t enough. To take care of this issue you need to use a lens that will create a false image a lot further away so that it doesn’t seem blurred for the naked eye.

Secondly there is myopia that is the complete opposite of hyperopia. This also can be easily corrected with a lens.

The third condition is astigmatism that isn’t so simple. The cornea or the lens is not regular, and for that reason it acts like multiple lenses that all have a different foci – the point where the lights that went through the lens meet. So for this reason we need to have specially made lens that can help with this issue.

Today the optics have evolved quite a lot and you can get toric lenses that are specifically designed for astigmatism – mostly custom made according to a prescription that you get from your doctor. Contact lenses have also take huge leaps and you can even get toric color contact lenses at a decent price these days. And unlike in the past you won’t have to wait for weeks to get them done, but the optician will prepare your lenses in a short time.

Contacts pose another problem when it comes to astigmatism, and that is the fact that since there are multiple planes where the light refracts, the lens has to be in a correct position to assure clear vision at all times. This has posed a few problems with contacts, but there are delicate mechanisms that allow the contact to be placed correctly each and every time.