A. Yes quite easily, if the equipment is to hand. But lens adjustments, and even polishing, are becoming increasingly uneconomic and most fitters will simply order new lenses for you.

Q. Can the power of soft lenses be changed? A. No.

Q. Why do soft lenses have a limited life?

A. Surfaces become permanently contaminated or pitted, edges become nicked, lenses tear, material becomes discoloured.

Q. What will happen if I let my soft lenses dry? A. They will turn into little grey potato crisps.

Q. Does that mean they are ruined?

A. By no means — unless you snap them. Just put them back into water, or a soaking solution and they will soon be restored to normal.

Q. What are comfort drops?

A. These are viscous solutions which help to keep the lenses wetted. They are sometimes helpful in building up wearing time.

Q. I wear soft lenses. Can 1 use medical eye drops?

A. Be careful! The preservative might concentrate in your lens and cause irritation. The active ingredient might also do the same, in which case you will get more than was intended.

Q. I get hay fever. Is it all right to wear my lenses during an attack? A. Between attacks — no problem. During an attack there is a risk of losing lenses if your eyes water or you sneeze much. A specialist could prescribe useful eye-drops.

Q. Can I wear my lenses if I have conjunctivitis?

A. Positively not. And make sure that they, and your lens containers, are sterilized before you wear them again.

Q. How?

A. Thorough cleaning, enzyme and boiling (if safe) for soft lenses; thorough cleaning and prolonged soakage in solution for hard lenses. Don’t forget the container!

Q. I have glaucoma. Should I wear contact lenses?

A. Ask your specialist. Sometimes soft lenses are undesirable, but they can be used to improve the delivery of medication.

Q. At what age can contact lenses be fitted?

A. Contact lenses have been successfully fitted to new-born babies, to ninety-year-old post-cataract patients and to people of every age in between.

Q. Yes, but apart from medical indications when should young people start?

A. People with moderate degrees of short sight might start around sixteen years, but if the myopia is severe, an earlier start is justified. But in this case an adult should supervise wearing time and routine cleaning of the lenses.

Q. Do young people have many problems with contact lenses? A. Young people are remarkably tolerant and have few problems. Those that arise are nearly always due to overwear andlack of cleanliness.

Q. Which kinds of people are least likely to be successful with contact lenses?

A. Males over 40. Teenage girls almost always succeed!

Q. I am short-sighted, 45, and usually take off my glasses to read. Do you recommend contact lenses?

A. No.

Q. Why not?

A. You will certainly need to wear reading glasses on top of your lenses.

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). As such it can take the place of the tight eyepatch formerly used to immobilize the eye to facilitate the recovery process. It is usually needed only temporarily until the condition being treated has cleared up. The lens is placed on the cornea by the ophthalmologist and is removed by the doctor when the disorder being treated has been cured.

Uses of Bandage Lenses

The lens has been used for many years with varying degrees of success to treat a great number of conditions. The most frequent uses are for:

Dry Eyes. Although I have cautioned against the use of a soft lens when tear production is reduced, this lens plays an important role in severe cases of dry eyes. The dry-eye syndrome is a common by-product of the aging process and affects women more often than men. In postmenopausal women all the mucous membranes begin to dry because of the shift in hormone production. In these cases dryness of the eye can become quite severe. A dry eye may also be caused by drugs (birth control pills, antihistamines, and so on), injury to or infection of the lachrymal glands, autoimmune disorders (Stevens-Johnson syndrome), severe injuries or infections of the eye, and vitamin deficiencies.

Eyes with a marked reduction in tear production can lead to damaged corneas. For patients suffering from dry eyes a bandage lens in tandem with frequent instillation of artificial tears is an excellent treatment. The eye drops are absorbed by the highly hydrophilic (water-loving) lens, bathing the eye with them in a more constant fashion than if drops alone were used.

Bullous Keratopathy. As a result of the aging process or following injury to the eye, which may be accidental or occur after intraocular surgery such as cataract extraction, the cornea may swell with an abnormal amount of fluid. The inner surface of the cornea (endothelium) becomes damaged, vision becomes blurred, and there is marked pain. The bandage lens can reduce and sometimes completely alleviate both symptoms by protecting the eroded corneal surface and by acting as a barrier to prevent fluid from escaping from the cornea.

Corneal Ulcers and Abrasions. The bandage lens seems to accelerate the healing process in abrasions and ulcers that can result from viral, bacterial, and fungal infections. This form of treatment should only be used in conjunction with antibiotic, antiviral, or antifungal eye drops.

Trichiasis. As a result of an injury, infection, or aging, the eyelashes may turn inward and rub against the cornea. A bandage lens can act as a shield while (or until) the primary condition is treated.

Chemical and Thermal Burns. By eliminating the constant irritation of the eyelid coming into contact with the healing corneal tissue, a bandage lens allows the cornea to grow back normally and more rapidly. Using a bandage lens postoperatively after a burn increases the success rate of such surgery.

Penetrating Corneal Wounds. When the cornea becomes wounded, a bandage lens aids in forming a protective shield and can be employed to facilitate healing when surgery has to be delayed.

Bell’s Palsy. When the upper lid is unable to close completely, the cornea may become overly dry. The bandage lens protects the cornea, but frequent instillation of artificial tears is necessary as an adjunct.

The “Contact Lens” as a Drug Deliver System

There now exist tiny discs containing special medication that may be placed on the eye to provide a constant source of medication. The small oval-shaped flexible “lens” is worn over the sclera under the eyelid. Its sole purpose is to act as a reservoir for drugs in liquid form, allowing specific amounts to be released into the eye gradually over a prolonged period of time. It’s really a time-release capsule for the eyes. The drug in use is, therefore, more effective than when it is administered as intermittent drops, because constant, round-the-clock treatment is possible. Also lesser amounts of the drug may do the job with this method. This can in turn reduce the local and systemic side effects and allow the use of more potent drugs such as steroids and glaucoma medication. Once in place the “contact lens” is a convenient way of administering medication, particularly for patients who might not otherwise comply with the prescribed treatment. Ocusert, containing the glaucoma medication pilocarpine, and Lacrisert, containing lubricating medication, are the two special “lenses” now commercially available. They can be worn continuously (even while sleeping) and removed and replaced weekly for the duration of the treatment.

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.

Though the eye is quite durable, it’s also an irreplaceable, delicate, sensitive, and highly sophisticated organ. Your eye is directly connected to your brain by the optic nerve and is closely related to other systems of your body. It shouldn’t be considered independently, and before you walk off with a pair of contact lenses you should undergo a complete medical eye examination by an ophthalmologist.

Such an exam is much more than a simple mechanical test of your eye as an optical instrument. It determines what prescription you’ll need. It also determines whether you’ll be able 26 to wear contact lenses safely and comfortably, and reveals clues that form a picture of your optical health and your physical condition in general. It also yields the measurements needed to “fit” you with the right pair of lenses—these measurements must be extremely accurate if you’re going to be comfortable wearing lenses. To do all this, your eye doctor uses a variety of instruments and techniques that may seem baffling and mysterious to the potential contact lens consumer. Space- age technology has invaded ophthalmology, and your eye physician’s examining rooms may resemble the inside of a spaceship; the instruments approximate cousins of Star Wars character R2D2, with futuristic beeps and digital readouts. Whether your doctor has the latest in equipment or not, the examination can be a fascinating process if you let it; and you should feel free to pepper him with questions.

History. This first step may seem casual and unscientific, but it’s very important. Your eye doctor will ask you “Why are you here?” and discuss with you your motivation, occupation, leisure activities, systemic diseases and medications, eye diseases and medications, and allergies, complaints about your vision, whether you get headaches, and whether you’ve worn contacts before, what type they were and any problems you had while wearing them. (If you do wear contact lenses, you should keep them out of your eyes at least twenty-four hours before your exam, though seventy-two hours is preferable.)

Refraction. This step determines the prescription your lenses will need to correct whatever refractive error—nearsightedness, farsightedness, astigmatism, or presbyopia—you may have. We’ve come a long way from the days when a simple wall eye chart sufficed. Nowadays the doctor usually first instills special eye drops that dilate your pupils before using the two instruments, the Phoroptor and the retinoscope, to come up with your lens prescription.

First comes the Phoroptor, that familiar contraption that makes the examinee look like the ultimate bug-eyed Martian. As you gaze at the eye chart (projected on the wall), the physician tries out several lens combinations, repeatedly asking you “which is better, first or second?” Out of its billions of possible lens combinations, the examiner determines and fine-tunes your prescription. After this subjective test (you’re judging which lens corrects the best), the results are read off the Phoroptor in order to check the prescription by doing an objective test for refraction. As your eyes gaze at a distant target through the prescription in the Phoroptor, the doctor peers into your eyes with the retinoscope. Through the dilated pupils the light of the retinoscope creates a measurable shadow and light movement on your retina, which enables him to check the accuracy of the prescription.

Curvature of the Cornea. Using a keratometer, an optical scanning device, the ophthalmologist determines the exact “topography” of the cornea. A system of mirrors measures the horizontal and vertical meridians of the cornea. This determines the steepness or flatness of the cornea and its degree of corneal astigmatism, an important part of the overall refractive error picture, and instrumental in determining whether you need a hard or soft lens.

Muscle Range and Coordination. How well do your eyes work together? Do they point to and focus at various distances equally? How well do you judge distance and space (depth perception, or stereopsis)? To find out, the eye doctor uses a muscle light and special prisms.

Outer and Middle Layers of the Eye. Next comes the slit lamp, an electrical microscope that lights up and magnifies your eyelids, cornea, iris, lens, and fluid of your eye in order to reveal any disease, damage, inflammation, or other abnormality. A special stain called fluorescein is used in conjunction with a cobalt-blue filter to detect any corneal defects or abrasions not visible with the naked eye.

Inner Layers of the Eye. Through the dilated pupil, the retina and its blood vessels can be seen with an ophthalmoscope, which illuminates and enlarges the doctor’s view. This is the point at which early signs of diabetes, hardening of the arteries, hypertension, and other general disorders of the body can be detected.

Eye Pressure. This is the “glaucoma test.” The doctor anesthetizes your cornea with special eye drops, and measures the pressure of the eye fluid with a tonometer. Though the instrument actually touches your cornea, you don’t feel a thing because of the anesthetizing eye drops. This test is especially important for anyone over the age of thirty, although it is unusual for glaucoma to occur before the age of forty. There is also a “noncontact” tonometer which utilizes a puff of air to measure the eye pressure. Although not as accurate as a tonometer, this instrument is an excellent screening device and eye drops are not instilled.

Tear Function. Tears lubricate and cleanse your eyes and also provide the cornea with oxygen. A sufficient supply of tears is a must for comfortable contact lens wear. “Dry eyes” can be countered with special eye drops if the problem is slight. To make sure it isn’t a contraindication, the ophthalmologist performs the Shirmer test: special strips of paper placed under the lids to gauge the amount of tear production. After about five minutes the test strips are removed and the amount of tear absorption is measured and evaluated.

Visual Field. In certain instances (suspicion of glaucoma, retinal abnormalities, optic nerve disorders, neurologic disorders, headaches, and so on) a test of your peripheral vision is important. To measure your peripheral (side) vision, a special computerized instrument is used. (If you like video games, you’ll love this part of the test. If you don’t, the challenge may leave you a bit limp.) First each eye is tested separately, then together. Your head is kept immobile as you face a large dome, perforated with a scattering of pin-sized holes. As you gaze ahead steadily at a red-lit cross in the center of the dome, minuscule flashes of light go off through the holes, one at a time, at various distances from the center cross. Every time you see a “star” light up in this mini-planetarium, you hit a button; meanwhile the computer keeps score by adding up the correct “strikes.”

Your ophthalmologist will evaluate all the information thus gleaned from all parts of the ocular examination and decide whether or not you—and your eyes—are a good candidate for contact lenses, and if so, what type. Those who “pass” the exam then go on to the next step, the contact lens fitting.