The types of contact lenses available today are nearly as numerous as the corrective issues they’re designed to correct. But today’s contact lenses don’t even need to be corrective in nature. Many are purely aesthetic, enabling a wearer to change eye color from brown to violet, for example, or to change from the appearance of human eyes into eyes that resemble that of a cat or wolf or even an alien!
Contact lens prescriptions include information on proper fit, measuring such attributes as curvature and diameter. But the prescription also contains other pertinent information such as proper measurements for correcting vision as well as the brand of contact lens believed most suitable for the patient’s situation.
It’s not necessary to understand all the different makes and models of contact lenses. That’s more the responsibility of vision specialists since they’re the ones responsible for making the final determination based on their training, knowledge and past experience.
There are several ways to categorize contact lenses. One way is to categorize contacts by material type. Plastic is the material of choice when it comes to contact lenses. Its fluid nature enables a more comfortable fit and its availability makes contact lenses more affordable. Plastic lenses fall into 3 general categories including gas permeable, hard and soft.
Another way to categorize contact lenses is by their wear and replacement schedules. As for wear schedules there are daily wear and extended wear lenses. Daily wear lenses are designed to be inserted and removed every day whereas extended wear contact lenses can remain in place for one to several weeks before removing.
And based on replacement schedules, there are disposable contact lenses and non-disposable. Daily wear disposable are worn once and then throw right away, completely eliminating the need for cleaning. Regular disposable contacts are worn several weeks before being thrown away. Again, the goal with disposables is less maintenance which lowers the risks of infection and other eye problems. Non-disposables require careful and regular maintenance as they don’t get replaced until torn or until a patient’s prescription changes.
And finally there are some special kind contact lenses. Theatrical contact lenses started out being designed for and used by actors and other performers. Giving eyes the ability to change from normal-looking to horrific and demonic, theatrical lenses are gaining in popularity among everyday users. Used primarily as a way to change a person’s look, the lenses generally are not designed for corrective purposes, but they do require a prescription for proper fitting.
Besides theatrical lenses, there are contact lenses that offer protection against damaging ultraviolet light – lenses called varichrome that darken when exposed to bright sunlight making sunglasses an unnecessary accessory, and contact lenses designed to change the color of one’s eyes.
Then there are the specialized contact lenses such as toric lenses that correct more troublesome astigmatisms, bifocal contact lenses which help a person see both close up and far away, spherical or aspherical lenses, and monovision lenses in which one lens assists with close up vision and the other lens is dedicated to distance vision.