A bandage lens, also called a therapeutic lens, is a special soft, very thin, high-water-content contact lens. In 1974 this hydrophilic lens was the first type to be used on an extended-wear basis, but without incorporating a prescription. It has a wide variety of uses before ocular surgery, after ocular surgery, and sometimes instead of surgery. It can also be therapeutic in conditions that do not respond to any other form of treatment.
The lens functions basically as a protective shield and prevents a damaged or ailing cornea from coming into contact with the eyelids and the air. Healing is thereby accelerated and pain is alleviated for as long as the lens is worn, which is on an extended basis (more than twenty-four hours). 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.
It is estimated that there are 8.5 million people in the United States who have some degree of color blindness. This is the common name given to the inability to distinguish colors and shades; some people have trouble with only a few colors, others see no colors at all. This inherited disorder affects mostly males: 8 percent of the male population is red-green color deficient, as compared with only one half of 1 percent of the female population. Read the rest of this entry »
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 »
“I know it must sound crazy, but few things in life have ever looked so good to me as the pattern of paint cracks in my bedroom ceiling. That was the very first thing I saw when I opened my eyes the morning after I’d slept while wearing my new extended-wear contact lenses. Seeing those mundane little cracks meant that I really could wear the lenses overnight. It was a dream come true and, in a sense, my life hasn’t been the same since.
Just before I got my new extended-wear lenses, the near-constant presence of big-city dirt and dust under my hard contact lenses had brought me to the verge of giving up lenses completely. I’d been wearing them for over ten years and was mighty tired of the old nightly and morning ritual too. At my next annual exam my doctor realized how unhappy I was and mentioned the availability of a new type of lens that was safe to wear while sleeping. He thought I’d be a good candidate; I nearly swooned with the good news . . . nearly fainted when I heard the price tag. But I decided to make the lenses a birthday present to myself. Read the rest of this entry »
Contact Lenses Care .
