The harmful effects of smoking on the health of the body are well-known. It comes as no surprise that smoking has been linked to eye disease, too. When we take a puff of a cigarette or exhale smoke, the smoke wafts upwards towards the eyes, making them water, burn, look red and feel gritty. While these effects are temporary and last only as long as the smoke exposure does, it is the toxic chemicals that are inhaled that cause lasting damage, travelling from the lungs to other parts of the body through the blood stream, and leading to biological changes in the body and the eyes. A number of chronic eye conditions are linked to smoking.
Dry eye is characterised by itchy, watery eyes, intermittent blurring of vision and a burning sensation in the eyes caused by insufficient tear production and/or poor tear quality. While it does not typically cause permanent vision damage, it is consistently irritating and uncomfortable. Exposure to smoke exacerbates the discomfort, but, more seriously, the tobacco chemicals interfere with the production of tears.
It has been found that there is a direct link between smoking and the development of cataracts, the clouding of the eye’s naturally clear lens. Symptoms of cataracts include blurry vision, difficulty seeing at night or in low light, and the appearance of colours as faded or dull. Smokers have been shown to have twice the risk of developing cataracts as non-smokers.
AGE-RELATED MACULAR DEGENERATION (AMD)
Smoking is a key risk factor for AMD, with smokers developing the condition on average 5 years earlier than non-smokers. AMD is a deterioration of the macula, the sensitive central area of the retina at the back of the eye which is responsible for central vision. Tobacco interferes with blood flow and causes oxidative stress, reducing the amount of oxygen and nutrients reaching the macula, gradually destroying central vision and resulting in distorted or blurred vision, blind spots and eventually vision loss. Research has shown that giving up smoking reduces the risk of macular degeneration.
Diabetic retinopathy is a progressive eye condition caused by uncontrolled elevated blood sugar levels which damage the blood vessels of the retina. The blood vessels break down, leak or become blocked, injuring the retina and permanently affecting vision. Smokers who also have diabetes risk developing diabetic retinopathy, and if they already have it, it may progress more quickly than in non-smokers.
Smoking can increase the risk of developing glaucoma, a condition typically caused by elevated pressure within the eyes. Glaucoma causes a gradual break-down of the optic nerve which is responsible for transmitting visual information from the eye to the brain where it is processed. As the nerve cells die, vision is slowly lost. Once damaged, the optic nerve does not heal; vision loss is permanent and irreversible.
SMOKING DURING PREGNANCY
Smoking during pregnancy may harm the unborn baby’s vision. It increases the risk of premature birth, which in turn increases the risk of the baby developing retinopathy of prematurity, an eye disease in premature babies characterised by abnormal blood vessel growth in the eye that can progress to vision loss.
The uvea is the middle layer of the eye which is rich in blood vessels carrying blood and nutrients to the eye. Uveitis is inflammation of the uvea causing it to become red, swollen and painful, and interfering with the flow of blood. It can damage the retina and the iris, exacerbate other eye conditions and result in vision loss. Toxins in cigarette smoke can cause tissue inflammation, doubling the risk of smokers developing uveitis.
Graves’ disease is a condition which affects the thyroid gland. Bulging eyes may be one of the symptoms, and this can become worse in smokers.
CONTACT LENSES AND SMOKING
Smokers who wear contact lenses are twice as likely as non-smokers to suffer from dry eyes, which may cause them to experience increased ocular irritation and discomfort with their contact lenses. Their risk of developing corneal ulcers is raised.
Many non-smokers experience irritation from secondhand smoke, but the effects may be more damaging than annoying, particularly for young children who have been found to show signs of smoke-related health problems, both in the body and in the eyes. New research suggests that secondhand smoke may damage children’s eyes and possibly lead to problems with vision later in life.
WORLD NO TOBACCO DAY ON 31ST MAY IS AN OPPORTUNITY TO “BE A QUITTER”!