By the time they reach their 80s, most Americans will have developed one or more cataract, a condition in which the eye’s natural lens becomes stiffened, cloudy, and difficult to see through. Cataracts are treatable with surgery to remove the eye’s natural lens and replace it with an artificial one. This surgery is quick and quite safe, with a high success rate and modest recovery time. Still, any surgery carries risk, and many doctors won’t operate until a cataract has become severe enough to interfere with daily life. That’s a lot to go through…worsening vision over the course of months or years followed by surgery, followed by recovery. And many people develop cataracts in both eyes, although cataract surgery is normally performed one eye at a time with several months in between, so they must undergo that process twice.
Are cataracts an inevitable sign of aging? What if you could prevent cataracts from forming in the first place?
Currently, there is no foolproof way of preventing cataracts. The potential for cataracts is essentially built into the biology of the eye’s natural lens. Throughout our lifetimes, more and more cells are generated and added onto the lens, which causes its proteins to thicken and stiffen, a process that typically begins in a person’s 40s, and an early stage of which is presbyopia, age-related farsightedness.
But just because cataracts form naturally doesn’t mean that everyone gets them when they age, and it doesn’t mean there’s nothing we can do to reduce our risk of developing them. While doctors and researchers understand the basic underlying mechanisms of how cataracts form, they are not completely sure why some people get them and others don’t, nor which lifestyle factors might drive up an individual’s risk. A good way of conceptualizing our current understanding is that cataract formation is a natural process that some people are more prone to than others, and that there are environmental and behavioral factors that might trigger or speed the formation of cataracts against that natural backdrop.
Sunlight. It has long been established that prolonged exposure to ultraviolet light from the sun’s rays greatly increases an individual’s lifelong risk of developing cataracts, yet how this happens has not become clear until fairly recently. What puzzled scientists was that the process by which lens cells clump and cloud looks like oxidative stress…to which lens cells should be immune. Oxidative stress is a natural process whereby cells produce harmful byproducts when they consume oxygen. But lens cells don’t consume oxygen, so how could sunlight be causing oxidative stress in them?
In 2014, researchers at Case Western Reserve University found that a form of sunlight called UV-A damages amino acid derivatives in the lens, triggering a process known as glycation which looks similar to oxidative stress and which brings on the cataract. This discovery could someday lead to treatments that prevent the eye’s proteins from clumping together. But for now, the best prevention we have is to protect our eyes from the sun’s harmful rays by wearing sunglasses that block both UV-A and UV-B light, as well as brimmed hats to keep the sun off our faces.
Diet. The eyes are nutrition-sensitive organs. You can improve your chances of preventing or forestalling the development of cataracts by eating foods high in B vitamins, vitamin C, vitamin E, omega-3 fatty acids, lutein, astaxanthin, zeaxanthin, and other antioxidants. The best way to achieve this is by consuming a varied, plant-based diet such as the Mediterranean diet, which is associated with reduced levels of biomarkers for inflammation and which helps prevent obesity, a risk factor for cataracts and other age-related eye diseases. But you can also target those nutrients by seeking out specific foods. These include leafy green vegetables such as kale and spinach, eggs, citrus fruits, avocados, walnuts, tea and coffee, carrots, salmon, and broccoli.
Smoking. Tobacco smoking is one of the worst things you can do to your eyes. Cigarette smoke contains many harmful chemicals that cause the proteins in the eye’s natural lens to deteriorate through the introduction of inflammation and free radicals. Smoke can also trigger a process called lipid peroxidation, in which cells in the membrane surrounding the lens die off, which is linked to cataract formation. Cigarette smoke even contains heavy metals such as cadmium, which can have a directly toxic effect on the eyes. Research shows that even heavy smokers can slash their risk of needing cataract surgery in half by quitting smoking.
Eye protection. In discussions about how to prevent cataracts, we often focus on diet and sunlight while giving short shrift to protecting our eyes from trauma. Yet around 65% of eye traumas lead to the formation of cataracts, usually through fluid retention and swelling of the lens fibers, and up to 1.6 million people per year lose their vision because of traumatic cataracts. To lower your risk, always wear safety lenses when doing dangerous work where shards, slivers, dust, pebbles, or chemicals could hit your eyes, as well as while pursuing shooting sports, ball sports, and other forms of recreation where there’s a danger of blunt objects striking your eyes.
People often ask how to prevent cataracts from getting worse once they’ve begun to develop. All of the above factors are just as important once you have cataracts as before they form.
Sometimes after people have undergone cataract surgery, they develop a condition called posterior capsule opacification (PCO), known colloquially as a secondary cataract. PCO is not the same as the primary cataract for which the person underwent surgery. Remember, cataract surgery consists of inserting an artificial lens in place of the one with the cataract, which means that the main biological process driving primary cataract formation no longer applies. Instead, the capsule inside the eye that once contained the lens with the cataract and now contains the artificial lens has become clouded by proteins left behind during the surgery. That’s easily fixed with a quick and painless procedure, but you may be wondering how to prevent PCO after cataract surgery. Unfortunately, there’s little you can do. Whether or not PCOs form appears to be linked in part to the shape and material of the lens used, as well as the surgeon’s technique. Follow whatever instructions you’re given for recovery, including using all medications exactly as directed. But don’t worry. If you’re among the one in five patients who do develop PCO, you can get it taken care of easily. Just stay in close contact with your doctor about any changes to your vision after surgery.
