What Can I Do to Prevent Cataracts?
Celeste Robb-Nicholson, M.D.
Q. Is it true that cataracts are made of calcium? Can I do anything to avoid getting a cataract? What about diet?
A. A cataract is a vision-clouding area in the lens of the eye. About half of all people ages 65 to 74, and 70 percent of those ages 75 and over, develop cataracts, which are the leading cause of blindness worldwide. Fortunately, surgery is safe and effective; in places like
Cataracts aren't made of calcium but rather of clumps of protein. Normally, the lens of the eye works like a camera lens to focus light on the retina at the back of the eye and to adjust the eye's focus, which allows us to see things clearly at varying distances. The cells of the lens are composed of water and protein arranged in a way that keeps the lens clear. For reasons that aren't fully understood, the protein molecules may clump together and start to cloud the lens. This is the beginning of a cataract. The effect has been likened to cooking an egg white.
The eyes see the light that objects reflect. Reflected light enters the eye through the cornea and lens and comes into focus on the retina at the back of the eye. The cornea starts the focusing process by bending the light at an angle determined by the cornea's curvature. The lens then fine-tunes the focus, further bending the light. Nerve cells in the retina send the light energy to the brain via the optic nerve.
You may not notice anything at first, but cataracts typically progress, becoming denser or clouding more of the lens and blurring vision. Eventually, vision may be so severely affected that surgery is needed to remove the lens and replace it with an artificial one. Cataracts usually form in both eyes but may not progress at the same rate or affect vision equally in both eyes.
We know how to treat cataracts, but we don't know much about why they develop. Aging is obviously a factor -- possibly because of changes in the chemical composition of the lens or possibly because of normal wear and tear. Most people develop some lens opacity, or clouding, by the age of 60. Other risk factors include injury to the eye, previous eye surgery, diabetes, use of corticosteroid drugs, and having a family member with cataracts. Many studies have implicated smoking and drinking as well. And a study suggests that hormone therapy may increase the risk. Cataracts also seem to be more common in people who've had long-term exposure to sunlight.
We don't know if avoiding or treating these risk factors will prevent a cataract from forming. But it can only do you good to refrain from smoking, moderate your alcohol consumption, and protect your eyes from sunlight with hats and sunglasses.
Evidence on the role of diet in cataract prevention is mixed. Some experts believe that antioxidant vitamins might help prevent cataracts by getting rid of molecules called free radicals, which may trigger or fuel protein clumping. But despite several studies, there's no convincing evidence yet that vitamin supplements prevent or slow cataract growth. In a 2008 Archives of Ophthalmology study, researchers found that women ages 50 to 79 whose diets were rich in lutein and zeaxanthin had fewer cataracts. These phytochemicals are abundant in dark green leafy vegetables such as spinach, kale, Swiss chard, watercress, and dandelion greens. But these vegetables contain many other healthy substances, so it's not clear whether lutein and zeaxanthin are responsible for the eye benefits.
In any case, you should have your eyes examined every two years (annually after age 60). And even if you can't do much to prevent or slow the growth of cataracts, you can reduce their impact on your life in various ways, such as adjusting your eyeglasses, getting anti-glare sunglasses or magnifying lenses, or just using brighter lights at home and work.
Harvard Health Letter
Available at Amazon.com:
- Living With Fibromyalgia: Take Steps to Limit Your Pain
- Is Heart Attack Going Out of Style?
- What Can I Do to Prevent Cataracts?
- For Vast Majority, Night Sweats Don't Represent Medical Concern
- Arthroscopic Surgery Often Good Option for Torn Rotator Cuff
- Diagnosis of Prediabetes Should Prompt Lifestyle Changes
- Is There a Solution for Watery Eyes?
- Fibromyalgia Symptoms Improve With Tai Chi
- What Can I Do to Stop Smoking if Standard Treatments Don't Work For Me?
- Try Natural Solutions For Insomnia
- Treatments Vary for Different Forms of Inflammatory Bowel Disease
- Be Aware of Signs and Symptoms Associated With Tick-Related Diseases
- Recovery From ACL Surgery Can Take Up to a Year
- Shake the Salt Habit
- Stomach Pain: When to Call the Doctor
- Is Not Washing Your Face Good For Your Skin?
- Should I Get The Shingles Vaccine?
- Pain in Finger Joints a Common First Symptom of Rheumatoid Arthritis
- Preventing Alzheimer's: 7 Risks to Consider
- Pancreas Transplant Doesn't Always Remove Need for Diabetes Treatment
- ALS Not Likely the Cause if No Other Symptoms Present
- Stents Useful Alternative to Temporary Colostomy In Some Patients With Colon Cancer
- Best Remedies for Back Pain
- Stop Insomnia - Inside the Mind of an Insomniac
- 'Bump' On Collarbone Not Uncommon After Fracture
- MLD a Rare and Serious Progressive Disease
- Sleep Apnea: Keeping Up the Positive Pressure
- Alternatives to Statins for Lowering Cholesterol
- Recurrence of Basal Cell Carcinoma Uncommon After Mohs Surgery
- Can Surgery Treat Type 2 Diabetes?
- Self-Care Techniques to Relieve Discomfort From Buttock Pain
- Artificial Lenses Have Long Been Used to Correct Vision
- Gene Mutation That Causes Huntington's Can Occur Spontaneously
- Is It Better to Stop Smoking Abruptly or Gradually?
- Brain Scan Alone Cannot Predict Likelihood of Dementia
- Is Sunscreen Dangerous? 4 Sun Protection Dos And Don'ts
- Low Platelet Count Not Necessarily Reason to Postpone Surgery
- Could Swimming in Cool Water Cause a Heart Attack?
- Bringing Psoriasis Under Control
- Best Summer Foods for Sensitive Stomachs
- Fight the Common Mold Allergy
- Largest Ever Cell Phone Cancer Study is Inconclusive
- Treating Early-Stage Esophageal Cancer
- TNF Inhibitors Offer Relief to Those With Rheumatoid Arthritis
- Prostate Exam Good First Stop When PSA Levels Increase
- 7 Nasty Germs That Could Land Your Kid in the Hospital And How to Avoid Them
- Secondhand Smoke A Serious Public and Personal Health Problem
- What to do About Excessive Belching and Feeling Full?
- Chest Pain: A Heart Attack or Something Else?
- Screening Plays Key Role in Detecting Polyps Before They Become Cancerous
- Learn How to Read Supplement Labels
- Compression-Only CPR Can Replace Conventional CPR in Many Circumstances
- Diabetes: Could You Have Diabetes and Not Know It
- Fighting Inflammation with Food
- Cortisone Injections Unlikely to Have Negative Affect on Bones
- Bad Health Habits Rob Years From Life Span
- The Importance of Decreasing Dietary Sodium
- Chronic Obstructive Pulmonary Disease (COPD): Takes Your Breath Away
- 7 Ways to Prevent Heart Disease
- Hypotension or Stiff Arteries May Cause Low Diastolic Blood Pressure
- Is It OK to Travel to a High Altitude With High Blood Pressure?
- Existing Drugs to Treat Herpes Are Very Effective
- Dry Mouth Can Be a Serious Problem
- 6 Simple Ways to Improve Symptoms of Fibromyalgia
- All About Gout: Old Disease Becoming More Common
- Frequent Monitoring Critical to Effectively Manage Scleroderma
- How to Identify Suicide Risk Before It's Too Late
- Tips for Natural Allergy Relief
- Inflammation May Play Role in Irritable Bowel Syndrome
- Bouncing Back After Being Sick
- Nicotine Patch May Offer Some Benefit to Ulcerative Colitis
- Common Myths and Misconceptions About Diabetes
- Vitamin E Supplements Not Recommended for Those With Diabetes
- Tick-Borne Disease Risk Peaks in Spring and Summer
- Meibomitis Creates Receptive Environment for Bacteria
- Top 4 Seasonal Allergy Mistakes
- Stress Less: Ten Strategies That Work
- Paralyzed Limbs Revived by Hacking Into Nerves
- Can Acid Reflux Damage my Esophagus
- Treadmill Test Can Reveal Hidden Problems in Heart
- Suffering From Allergies? Tailor Treatment to Your Symptoms
- Researchers Break Through to Unconscious Patients
- Key Factors Related to Heart Attack Risk
- Type 2 Diabetes Increases Risk for Cardiovascular Problems
- Hypochondria: The Impossible Illness
- Surgeries Can be Combined But May Not be Necessary
- Is Heartburn Surgery the Answer?
- Best Cooking Methods for Heartburn Sufferers
- 14 Things You Might Not Know About Aspirin
Copyright © 2010 Harvard Health. All rights reserved.