Daily-Wear Contact Lenses. Conventional hard lenses, gas- permeable lenses, and soft lenses can be worn to correct vision following a cataract removal. But the problem of daily insertion, removal, and cleaning is a real one, and discourages many a potential daily wearer. Fear of inserting a foreign object into the eye; diminished dexterity; reluctance to handle tiny, delicate, almost invisible objects—all can add up to a less-thansuccessful scenario. The replacement rate with soft lenses is particularly high: the average life span of a pair is two years because of loss, torn lenses, or lens deposits. Because of their advanced age aphakes often have dry eyes, and soft lenses require a more lavish tear supply than do hard lenses. Also, loose lids, usually found as a product of aging eye, can cause fitting and wearing problems.

Many aphakes do, however, adjust to life with daily-wear contact lenses. Sometimes a willing friend or relative helps with the lens care and handling. Aphakes also have some distinct advantages to mitigate their particular problems when it comes to contact lens wear. Since the cornea has been cut (and nerves severed) during the cataract extraction, the eyes are less sensitive and contact lenses feel more comfortable. (Unfortunately this desensitization may mean that the aphake is less aware of any injury and damage to the eyes; therefore these patients require careful monitoring.) For those who can’t cope, there are two more alternatives: extended-wear contact lenses, and intraocular lenses.

Extended-Wear Contact Lenses. As discussed previously this is a recent development, and many eye practitioners feel that these lenses are the safest alternative. As such they have become the single most frequently prescribed form of contact lenses for aphakes. And with good reason: extended-wear contact lenses are comfortable and provide good visual acuity. Primarily they solve the biggest drawback of aphakic contact lens wear by eliminating the daily insertion, removal, and cleaning required of all other types of contact lenses. In fact, extended wear for aphakes was FDA approved before extended wear for so-called “cosmetic” use because of the very real and greater need for this type of lens.

Extended-wear contact lenses are initially inserted at the doctor’s office and worn continuously for up to one month or more. During periodic eye examinations at the doctor’s office the lenses are usually removed and cleaned and then reinserted. As with daily-wear lenses, sometimes a neighbor or a relative is enlisted to help remove, clean, and insert the lenses between office visits.

Extended wear does have its drawbacks. The lenses currently available will not fit everyone, but they are successful in an estimated 75 percent of the aphakic population. Since they wear them for longer periods of time, aphakes tend to have even more of a problem with protein deposits than normally occurs with the daily-wear lenses. The useful life of the lens is thus shorter, necessitating frequent replacement, though the “saline eyewash” has been shown to be an effective preventive that can be used without removing the lens. Wearers should be hygiene conscious and be willing to go to the doctor for the needed follow-up visits.

Intraocular Lenses. Although they are not contact lenses, plastic intraocular lenses are quite similar and offer a viable and permanent solution for the aphake. Each year a larger percentage of those who undergo cataract removal will have a lens implant, usually at the time of cataract surgery. As a result they have a new substitute lens built right into the eye; quite often vision is restored to 20 / 20 without glasses. This is the most convenient form of cataract correction, since the lens is never removed unless complications ensue.

The intraocular lens is the brainchild of the English ophthalmologist Harold Ridley, who developed the idea during World War II. He saw wounded RAF pilots with fragments of Plexiglas windshields embedded in their eyes. The plastic remained inert, which led him to the conclusion that intraocular lenses could be made from the same material (polymethylmethacrylate, or PMMA, the same plastic from which conventional hard contact lenses are made) and safely placed into the eye.

Since ophthalmologists do not know the long-term effects of intraocular lens implants, the best candidates for ocular implants are the elderly. If they have dry eyes and eyelid abnormalities, which preclude wearing contact lenses, the lens implant will be the best type of vision correction. On the other hand those who are very nearsighted, have detached retinas, poorly controlled glaucoma, diabetes, or other eye diseases, are advised to seek the other vision-corrective devices mentioned earlier.

About 10 percent of the intraocular implants result in complications. Many of these can be corrected without removing the implant. They may include dislocation of the implant, changes in the cornea, inflammation of the iris, retinal detachment, and increased pressure in the eye that could lead to glaucoma. At times the intraocular lens will have to be removed. Tests are still being conducted to study the longterm effects of intraocular lenses.

Future developments in this field lie mainly in the improvement of the lenses themselves. Another method of vision correction involves grafting “live” contact lenses onto the aphake’s cornea. Donor corneas are frozen and ground to size, then sutured onto the living host cornea. To date several such operations have been successful.