Your vision depends on light beams hitting the retina (the back of your eyeball) at the same point. When the light does not meet at the same point, vision becomes blurred.
To correct this vision problem a lens needs to be placed in front of the eye to compensate. The lens then becomes a 'perfect' eye and light beams converge together at the retina.
Even though eye glasses have long provided the needed correction for vision problems, contact lenses were a marvel of science allowing individuals the freedom to forgo the hassle of slipping, fogging and distracting eye glasses. The inside surface of the contact lens is fitted to the shape of your eye so it stays in place. The outer surface is shaped to the corrected curve (as in eye glasses).
Originally, these contacts were made of hard plastic that required saline solution drops on a regular basis to keep moist. They were also prone to 'popping' out and causing discomfort when blinking. Newer contacts are made from a soft plastic that allows the eye to 'breathe'. They are much more comfortable to wear and because of the high water content of the material they require less maintenance during use. Soft contacts cling to the layer of tears covering the cornea and move slightly with each blink. This ensures that the eye stays moist and foreign materials can be safely washed out.
Basically, the purposes of contact lenses are to correct common vision problems like short-sightedness (myopia - when a person can focus on objects close to them but not far away) and far-sightedness (hyperopia - where the individual can see well at a distance but has trouble focusing clearly on print and other close objects). Now even individuals with astigmatism (where the shape of the cornea is elongated) or presbyopia (an age related condition that used to require bi-focals) can find contact lenses to suit their unique needs.
Currently, contacts are now developed in a disposable variety that means no cleaning is required. There are also contacts that can be worn for a week or even a month without being removed and cleaned - great for those who hate the daily hassle.
Many contact lens wearers are experimenting with changing the color of their eyes. While older versions produced harsh colors, new versions of color contacts (which can even be worn by individuals who have no vision problems) can be found in subtle shades and can even change dark eyes to light.
The contacts will be improved in the future. There is even talk of contacts created to prevent conditions like myopia from developing in children. Whatever happens, those with vision problems can count on new solutions being added to the currently available options all the time.
