1. A contact lens is designed to rest on the cornea, the clear outer surface of the eye.
2. Contacts are held in place mainly by adhering to the tear film that covers the front of the eye and, to a lesser extent, by pressure from the eyelids.
3. As the eyelid blinks, it glides over the surface of the contact lens and causes it to move slightly. This movement allows the tears to provide necessary lubrication to the cornea and helps flush away debris between the cornea and the contact lens.
4. A contact is an optical medical device, primarily used to correct myopia, hyperopia, astigmatism and reading problems. In these conditions, light is not focused properly on the retina, the layer of nerve endings in the back of the eye that converts light to electrochemical impulses. When light is not focused properly on the retina, the result is blurred or imperfect vision.
5. When in place on the cornea, the contact lens functions as the initial optical element of the eye. The optics combine with the optics of the eye to properly focus light on the retina. The result is clear vision.
6. What causes farsightedness? Hypermetropia most commonly occurs because the eyeball is too short; that is, shorter from front to back than is normal. In some cases, hypermetropia may be caused by the cornea having too little curvature.
7. Replacing contact lenses frequently usually means better eye health. Other obvious advantages are having spare ones immediately available should one get torn or lost.
8. Be sure you wear your back up eyeglasses at least once a week to give your eyes and cornea a chance to reoxygenate.
9. Symptoms of overwear include burning eyes, dryness, blurred vision and seeing halos around lights. This can lead to serious corneal problems and infections. Consult your eye doctor regularly for eye examinations and follow up care.
10. Frequent and Planned Replacement contacts are replaced on a planned schedule, most often every two weeks, monthly or quarterly. These items usually come 4 to 6 per box. Eye care professionals may recommend enzyming them if they are used longer than one month.