Q: Why is it harmful to rub the eyes while wearing contact lenses, even soft ones?
A: There are several reasons: (1) Because of the aforementioned blepharoptosis, (2) because an abrasion may occur, and (3) because of the possible introduction of bacteria, fungi, or viruses.
A: That depends upon the lens and your eyes. Most people are eventually able to wear their lenses most of their waking hours: about eight hours for hard-lens wearers and fourteen hours for soft-lens wearers. But every pair of eyes is unique. Some people can wear their lenses for only four hours a day; some can go for as long as eighteen hours, though this is not a good idea unless you break up the time with a rest period. This method can be used by anyone to effectively extend wearing time: Remove your lenses and let the eyes rest for fifteen or twenty minutes. This gives them a new lease on life, and lets you wear your lenses late at night after a long day at the office. Read the rest of this entry »
A: Contact lenses are dangerous if you have a faulty lens, or do not maintain proper ocular hygiene, or don’t follow the recommended wearing and handling procedures. For instance, corneal abrasion can occur when the lens isn’t inserted properly. Corneal edema occurs if you overwear the lens. An eye infection may be caused by fingers or contact lens solutions that are contaminated. And foreign bodies can sneak under the lens and irritate the cornea.
With regard to the vast number of contact lens wearers, though, such complications have been remarkably rare. Read the rest of this entry »
Keratoconus is a relatively common hereditary disorder that manifests itself in adolescence. It affects both eyes, but one eye usually progresses faster than the other. During the course of this disease the cornea changes from its round shape to that of a cone, hence the name: kera meaning “cornea” and conus meaning “cone.” The apex of the cone is thin and may become scarred. In severe cases the apex may actually perforate.
The poor vision brought on by keratoconus is due to a highly exaggerated form of astigmatism that is poorly corrected by glasses. Until contact lenses became available, keratoconus patients often had to be satisfied with partially corrected vision and led less-than-normal lives. But contact lenses can provide almost perfect vision in most cases and are the best means of vision correction for this disorder.
Hard contact lenses are usually used because the smooth, dome-shaped shell plus the tears beneath it provide a new smooth, round refracting surface for the eye. Because the cornea is diseased, the eye may not tolerate conventional hard lenses. In that case gas-permeable contact lenses may be prescribed instead. Soft contact lenses, in general, do not work well with keratoconic eyes. As is the case with astigmatism, the pliable material from which they are made conforms to the misshapen cornea, duplicating the refractive error. Soft contact lenses may, however, correct a portion of the faulty vision. And in some cases the patient is fitted with hard lenses on top of the soft lenses, piggyback fashion, to take advantage of the comfort of the soft lens plus the sharp visual acuity provided by the hard lens. In all cases the lenses are difficult to manufacture, and the fitting process must be extremely exact to achieve acceptable results.
Eventually everyone experiences presbyopia. This is the normal aging process of the eye, which begins around the age of forty for most people, and is caused by the gradual loss of elasticity in the natural crystalline lens of the eye. The lens loses its ability to change shape the way it used to, and fails to bring the light rays of near objects into sharp focus. Of course a nearsighted person over the age of forty can see near objects clearly with the naked eye, but will have difficulty doing so if he is wearing glasses or contact lenses that correct his myopia. Read the rest of this entry »
Contact lenses are, in most cases, a far better solution once the aphake is convinced that the “newfangled” device is worth trying. Advantages are the normal appearance of the eye and crisp visual acuity. Since only 6 percent magnification of objects occurs, the images appear to be of normal size, fusion can take place, and excellent peripheral vision and depth perception will result. Therefore life can go back to normal, the cosmetic effect is far better, and most observers can’t tell that there’s ever been a cataract extraction. Read the rest of this entry »
Contact lenses that you can wear while you sleep—this earth- shattering concept arouses no less interest and excitement than the Pill did when it was first introduced. This is the glamour lens that everybody wants to know about and have, and is probably the lens of the future. Like the Pill, which forever altered our sexual standards, the extended-wear contact lens promises to usher in a new era and change our attitudes toward visual correction. But the similarity doesn’t end there: Though this lens seems to be the answer to every contact lens wearer’s prayers, it has not yet been perfected. It is definitely not for everyone, and some practitioners are reluctant to prescribe it at all.
Canada, Australia, and Europe enjoyed several types of extended-wear contact lenses several years before we did. However, there is no Food and Drug Administration in those parts of the world, and because of this lack of strict monitoring control and quality, these lenses have posed a health problem, especially as related to corneal complications. Read the rest of this entry »
Contact Lenses Care .
