When I wore hard contact lenses, the optometrist told me to blink often and completely. With my new soft lenses he says I don’t have to blink so much. Why?
-Your old hard lenses prevented essential oxygen from reaching the cornea; blinking solved the problem by circulating oxygen-filled tears under them. By contrast, soft lenses have a high water content which allows oxygen to dissolve in the lens itself and to pass right through to the cornea where it is needed. Hard gas-permeable lenses, like soft lenses, also allow oxygen to reach the cornea.
I have been told that I cannot wear soft lenses. Why would this be?
-You probably have astigmatism, or an irregularly shaped cornea, in which case regular soft lenses won’t fit the contour of your eye. A newer type of soft lens does correct high degrees of astigmatism in many patients, but the lenses are expensive, hard to fit, and sometimes poorly tolerated. Regular hard contacts or gas-permeable lenses are worn by many people with astigmatism.
I understand that contact lenses cannot be used as reading spectacles. Is this true?
-No longer. Thanks to a fitting procedure called monovision, there are people today who are wearing a contact lens focused for near vision in one eye only, while they use the other eye for distance vision. For those who require a double correction, one lens can be prescribed for near and the other for distance seeing. Also available are bifocal contact lenses, but these are not very satisfactory; they are more difficult to fit and it takes longer to get used to them.
Is it true that some people develop serious problems from wearing contact lenses?
-You are probably thinking of the widely publicized corneal ulcers associated with extended-wear contact lenses. These ulcers on the cornea are caused by an infection that may develop when contact lenses are worn too long, usually against doctor’s orders. Although extended-wear lenses are responsible for the condition in many cases, all lenses, if not worn and cared for properly, can cause problems.
My son needs a new prescription for these contact lenses. Why does his optometrist want him to go without for a while and wear his old glasses?
-To fit your son for new contact lenses, the optometrist must remeasure his cornea, whose shape the lenses have distorted. It may take some weeks for the cornea to regain its normal shape (a few days if the old lenses were soft). Once the shape of the cornea stabilizes, the optometrist can fit the new contact lenses. Contact wearers should keep a pair of regular glasses for such eventualities.
A friend told me that a contact lens could get lost in the back of the eye. Is this true?
-Many people seem to think that contact lenses can slip inside the head. This is nonsense: it is impossible for a lens to float to the back of the eye, since there is an eye membrane in the way. Lenses can sometimes slip under an eyelid, however.
Is it worth shopping around for the best buy in contact lenses?
-By all means, shops around until you are satisfied you are dealing with an optometrist or ophthalmologist experienced in prescribing contact lenses and providing thorough care. When shopping around, be sure to ask what the total charges for the contact lenses will be, including fittings, adjustments, replacement costs for lost lenses, and equipment necessary to clean and care for them.