How Contact Lenses Work
A simple, easy-to-understand explanation of contact lenses

Contact lenses are little, thin transparent discs, that are designed to sit on your cornea, the clear covering over your pupil, and correct your vision. The cornea is able to withstand the placement of the contact lens since the surface as tough. In fact, the moisture in your eyes acts as glue that keeps the lenses in place. To a lesser extent, your eyelids help to keep them in place, too. However, your eyelids play an important role in keeping your contacts clean. Every time you move your eyelids, they slightly move your contacts. This keeps them in uniform moisture while washing away any foreign substance lodged between the lens and your cornea.
Your contact lens’ actual shape is determined by the actual shape of your eye. The shape must be uniform if the lens is to stay in place, and the inner surface of the lens is fit to the shape of your eye. The outer surface of the lens is designed on a smaller scale to your eyeglasses and helps your vision.
People wear glasses or contact lens with the same aim—to correct vision defects. Many people find wearing eyeglasses a hassle if they need them for a variety of activities. Having them slide down their nose or fogging up in the wintertime, or taking them off and putting them on constantly throughout the day can be frustrating. However, with contact lens, people can have the vision correction they needed without the hassle of eyeglasses.
About Contact lens technology
The first modern set of contact lenses was originally made of hard plastic. This was hard on the eyes and required a lot of maintenance to prevent eye irritation. A saline solution was applied frequently to keep the eyes moist.
With the development of soft flexible contact lenses, the range of possibilities expanded. Soft contact lenses, made from a gel-like plastic that contains from 38%-79% water, are more comfortable than hard plastic lens and last longer, too.
There are several different types of contact lenses and some of these are listed below:
Disposable lenses are replaced every day, every few weeks or every few months
Daily-wear lenses should be removed nightly

Oxygen permeables transmit oxygen. As they don’t contain water, they resist deposits and bacteria
Color-tinted lenses are usually utilized for cosmetic purposes and they change the natural eye color
Disposable contact lenses with ultra-violet absorber protects against the sun’s ultra-violet rays
These contact lenses listed above are the most common types of contact lenses. However, there are also some specialty contact lenses used for special theatrical effects in movies or elsewhere. More new types of contact lenses are being invented every day.