How contact lenses work
"Perfect vision" occurs when light rays converge at a point directly on the retina (on the back of eyeball). About four in ten people have "perfect" vision. For the rest, clear vision may be achieved by refocusing light rays using corrective lenses. Contact lenses are delicately crafted, very thin optical discs about the diameter of a shirt button. They are comfortably held in place by the eye’s own natural tears, which are always present between the lens and the eye.
The superior quality of today’s lenses, combined with professional fitting and aftercare, ensures your lenses will be properly prescribed for ultimate fit and comfort. Your eye care practitioner has many lens options to choose from in determining which one best suits your vision needs and your lifestyle.
Most common vision conditions can be treated with contact lenses, and in the last few years, technological advances have produced many more options for treating each kind of problem. Your eye care practitioner can tell you more about the range of options available for any of these conditions:
As people age, their eyes lose their ability to shift focus between far and near objects. Also called "ageing eye", this is a natural process which creates difficulty in reading small type, for example, or shifting focus between the road and a car’s speedometer. For these people, their only option used to be prescription spectacles with bifocal lenses or "reading glasses". But now there’s good news for those who will be affected by presbyopia as for many the condition is correctable with today’s bifocal contact lenses. These lenses are individually prescribed for each person’s special combination of distance and near vision, and several types of lenses are available.