Encyclopedia of Family Health - Vol. 3

By David B. Jacoby; Robert M. Youngson | Go to book overview

Contact lenses

Questions and Answers

Can anyone wear contact lenses?

No. Some people simply cannot
tolerate them—particularly the
hard type—because of unusual
sensitivity to discomfort. Other
people have a medical condition
that prevents them from wearing
contact lenses—for example, those
with allergies, hay fever, sties, or
disorders such as excessive
watering or bloodshot eyes.

If my daughter starts wearing
contact lenses, will they stop her
from becoming more nearsighted?

Unfortunately not. If her
nearsightedness is hereditary and
her eyesight is very poor, contact
lenses will not prevent any further
deterioration. If she does not like
wearing glasses, however, contact
lenses might be advisable for
cosmetic purposes.

Can I sleep while wearing my
contact lenses?

Most people remove their lenses
at night for cleaning and reinsert
them the following day. Napping
while wearing lenses is common,
but not everyone can tolerate this.
Long-term-wear lenses are now
condemned by ophthalmologists
because of the high incidence of
complications, some serious. Very
thin soft lenses with a high water
content may be worn quite safely
for a day or two, but continuous
wear is not recommended.

My soft lenses once caused
abrasions on my eyes. Why did
this happen?

Soft lenses require extra
maintenance and a high standard
of hygiene. Sometimes a film can
build up on the surface, causing
pain and swelling in the eye. Hold
your lenses up to the light—if
they appear cloudy or speckled, it
is probably best to replace them.

Many people prefer contact lenses to glasses because they feel that contact
lenses improve their appearance. Observing high standards of hygiene and
avoiding prolonged use are important if contact lenses are to be worn safely
.

A contact lens is a lens that fits over the front of the eye and is used in place of eyeglasses. Contact lenses are made of plastic and come in many colors.

Many people wear contact lenses for cosmetic or professional purposes, or for sports. They may also be worn for optical, medical, or surgical reasons.

Contact lenses can be used in cases where the iris has been lost through an accident or operation, because they can be custom-made to stop too much light from entering the eye. Similarly, cases of albinism—a rare condition in which the skin and hair are white and the irises red, making a person oversensitive to light—can also be aided by the use of special contact lenses.


Who can wear contact lenses?

People of any age can wear contact lenses, depending on individuals’ state of health. They can be worn by people with myopia or nearsightedness, near-vision problems or hyperopia, corneal curvature anomalies or astigmatism, and even conical cornea or keratoconus, (see Eyes and Eyesight).

However, not all eyeglass wearers can actually tolerate contact lenses. They are unsuitable for people who have allergies, such as hay fever, which cause the eyes to run, or recurrent sties or other eye disorders, which the lenses might aggravate.

Before insertion, a hard
contact lens is held on the fingertip (top). In the eye (above),
it is hardly noticeable
.


Choices available

Contact lenses are usually prescribed by an ophthalmologist (eye specialist) in either a hard or a soft variety. Hard lenses, made of an inflexible piece of plastic, are smaller, last longer, are less likely to cause infection, give excellent vision, and are less expensive than soft lenses. However, it takes longer to build up a tolerance to them.

Soft lenses, which are more pliable than hard lenses, are easily fitted to the eye. They can be tolerated more quickly and are infinitely more comfortable, even when first put in. However, the vision achieved is not as fine with soft lenses, and eye infections occur more frequently. Soft lenses are also likely to tear and do not last as long as hard lenses.

In the past, continuous-wear contact lenses were widely advertised and, for a time, seemed acceptable. More recently, experience has shown that problems are eventually likely to arise. In particular, wearing soft contact lenses for long periods can result in infection by an amoeba in the genus Acanthamoeba, which can cause serious corneal damage. There has been so much concern that some manufacturers are now offering “wear for a day and throw away” soft lenses.

Contact lenses can also be harmful if they cause abrasions of the tissues. Prolonged wear or wearing dirty lenses can lead to eye inflammations. Such complications occur rarely and are more common in the first two years.

Hard lenses, which are inserted into the eye with a lubricant wetting solution, must be cleaned daily. Soft lenses require a special nonirritant soaking solution.

See also:Allergies; Hay fever; Inflammation;
Lazy eye; Ophthalmology; Sty

-406-

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Encyclopedia of Family Health - Vol. 3
Table of contents

Table of contents

  • Title Page *
  • Contents *
  • Bronchitis 294
  • Brucellosis 297
  • Bruises 298
  • Bunions 299
  • Burn Center 301
  • Burns 303
  • Burping 306
  • Bursitis 307
  • Calcium 310
  • Cancer 312
  • Capillaries 318
  • Cardiac Massage 320
  • Carpal Tunnel Syndrome 322
  • Cartilage 324
  • Cataracts 326
  • Celiac Disease 329
  • Cells and Chromosomes 330
  • Cellular Telephones 333
  • Cerebral Palsy 335
  • Cervix and Cervical Smears 337
  • Cesarean Birth 340
  • Chat Room 343
  • Chelation Therapy 345
  • Chest 347
  • Chicken Pox 349
  • Child Abuse 351
  • Child Development 354
  • Chinese Medicine 358
  • Chiropractic 362
  • Cholera 365
  • Cholesterol 366
  • Chorionic Villus Sampling 367
  • Chronic Fatigue Syndrome 369
  • Chronic Obstructive Pulmonary Disease 370
  • Circulatory System 372
  • Circumcision 374
  • Cirrhosis 375
  • Cleft Palate 376
  • Cloning 377
  • Clubfoot 379
  • Cocaine and Crack 380
  • Cold Sores 382
  • Colon and Colitis 383
  • Colonic Irrigation 384
  • Colonoscopy 386
  • Color Blindness 388
  • Color Therapy 390
  • Colostomy 392
  • Coma 394
  • Common Cold 396
  • Complexes and Compulsions 397
  • Conception 399
  • Congenital Disorders 401
  • Conjunctivitis 403
  • Constipation 404
  • Contact Lenses 406
  • Contraception 407
  • Convalescence 412
  • Convulsions 413
  • Coordination 414
  • Cornea 416
  • Corns 417
  • Coronary Arteries and Thrombosis 419
  • Cosmetics 422
  • Cosmetic Surgery 424
  • Coughing 426
  • Cough Syrup 427
  • Counseling 428
  • Index 431
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