When the smoke gets in your eyes
Exposure to cigarette smoke is a major risk factor for serious vision problems that can lead to blindness, said Victor Malinovsky, clinical professor in the School of Optometry at Indiana University in Bloomington. For example, regular smokers are twice as likely to develop Type II diabetes, three times as likely to experience age-related macular degeneration, and more than 16 times as likely to suffer ischemic optic neuropathy, a sudden-onset disease that can cause total vision loss in one or both eyes.
"Casual smokers and people exposed to second-hand smoke also have greatly increased risk of many eye diseases," Malinovsky said. "There are so many components in cigarette smoke that are toxic -- nicotine, carbon monoxide, tar -- and they alter the nutrients that need to reach the eye; they upset the eye chemistry. An even bigger problem is the damage to blood vessels from smoking. The vessels behind the eye can be compromised, which cuts off the flow of oxygen to the eye."
Below, Malinovsky describes a number of diseases affecting vision for which smoking is a leading risk factor. He noted that quitting smoking or reducing exposure dramatically reduces the risk of developing these diseases
- Macular degeneration. "Age-related macular degeneration is the leading cause of blindness among older adults. The two major risk factors are age and smoking. We currently don't have a good treatment for this disease. It affects central vision so that a blind spot develops right in the front of the field of vision. You may be able to move around, but your livelihood will be affected as well as reading and driving -- most activities of daily life.
- Diabetic retinopathy. "The risk of developing Type II diabetes increases with the amount of smoke exposure. Smokers who develop diabetes also have earlier onset than non-smokers who develop the disease. With diabetic retinopathy, the blood vessels behind the eye become leaky. The tissue around the broken capillaries swells and can distort vision. At the same time, capillaries can't get any oxygen to the back of the eye, so the cells begin to die."
- Cataracts. "People who smoke 20 or more cigarettes per day are more than twice as likely to develop cataracts compared to nonsmokers. The toxic elements in cigarette smoke destroy the antioxidant nutrients that are essential to lens transparency."
- Glaucoma. "Glaucoma is another leading cause of blindness that is correlated to smoking. Glaucoma involves damage to the optic nerve. The blood vessels that supply the optic nerve can be damaged from smoking."
- Ischemic optic neuropathy. "Ischemic optic neuropathy is a disease of the optic nerve that comes on very suddenly. You can wake up and your vision is gone, or half your field of vision is gone. What happens is that the blood vessels close suddenly, and the blood supply to the optic nerve is completely cut off. It is a rare disease, but it is 16 times more likely to occur among smokers than nonsmokers, and smokers tend to get it in their early 50s rather than their mid-60s. If you are smoking and you develop this condition in one eye, you know you need to stop, because the other eye is at risk."