SMOKING AND EYE DISEASE

Cigarette smoking and vaping are both potentially damaging to the eyes. While tobacco smoke is a hazardous mixture of over 5,000 chemicals, vaping solutions do not produce tar or carbon monoxide but often have much higher nicotine levels than cigarettes as well as other chemicals with known and unknown negative effects. Toxins enter the blood stream and are carried throughout the body damaging both blood vessels and various parts of the body, including the delicate light-sensitive tissue of the eyes. Smoking reduces the body’s absorption of nutrients essential for eye health.

DRY EYE

A short-term effect of smoking is the development or worsening of dry eye syndrome, a common eye condition caused by insufficient lubrication of the surface of the eyes. Exposure to smoke irritates the eyes, leading to dryness, scratchiness, redness, blurred vision, light sensitivity and excessive watering, all of which cause particular discomfort in contact lens wearers.

CATARACTS

A cataract is the clouding of the eye’s naturally clear transparent lens, gradually leading to cloudy or blurred vision, sensitivity to light, difficulty seeing at night or in low light conditions, and perceiving colours as faded.

Most people develop cataracts as part of the normal aging process, but people who smoke have an increased risk of cataract development and are more likely to develop them earlier than non-smokers.

As well as increasing the number of damaging free radicals in the eyes, smoking can destroy the antioxidants which fight these free radicals.

MACULAR DEGENERATION

Smoking is the major preventable risk factor for age-related macular degeneration (AMD), an eye disease that gradually destroys the macula, the most sensitive part of the retina that is responsible for sharp central vision.

It typically occurs later in life, but smoking and vaping can increase the risk of it developing earlier as well as increasing the likelihood of developing it by up to four times. The condition can either cause the retina to deteriorate (dry macular degeneration) or result in excess blood vessels growing under the retina (wet macular degeneration).

Research suggests that people who smoke have lower levels of the macular pigments lutein and zeaxanthin, which are responsible for protecting the macula from harmful ultraviolet (UV) radiation.

GLAUCOMA

Glaucoma gradually damages the fibres of the optic nerve which conveys messages from the eyes to the brain. While there is no conclusive evidence that smoking or vaping itself increases the chances of developing glaucoma, research has shown that smokers have higher intraocular pressure, one of the major risk factors for glaucoma.

DIABETIC RETINOPATHY

Diabetic retinopathy is a complication of diabetes in which the tiny blood vessels that supply the retina are damaged by high blood sugar levels, causing them to leak blood and fluid into the eye and eventually leading to partial or total vision loss. As well as increasing the risk for diabetes, smoking is a significant risk factor for developing diabetic retinopathy in type 1 and type 2 diabetes.

UVEITIS

The uvea is the central layer of the eye which is rich in blood vessels carrying blood and nutrients to the eyes. As well as causing uveitis, an inflammation of the uvea which can damage the iris and retina, the harmful chemicals in cigarettes can exacerbate other eye conditions and lead to cataracts, glaucoma and retinal detachment.

THYROID EYE DISEASE

There is strong evidence of an association between smoking and the development of thyroid eye disease, a rare autoimmune condition in which the eye muscles and fatty tissue behind the eyes become inflamed, leading to protrusion of the eyes, double vision and vision loss. Usually linked to the thyroid disease, Graves’ Disease, it can occur in people with a normally functioning thyroid.

PASSIVE SMOKING

Although non-smokers often complain of eye irritation when exposed to the smoke of cigarette smokers and vapers, there is no evidence to suggest a direct link between second hand smoke and eye disease. However, smoke is one of the allergens in allergic conjunctivitis, which is characterised by itching, burning, redness, watering and swollen eyelids.

It has been found that quitting smoking can considerably reduce the risk of developing certain eye diseases and slowing the progression of others. Adopting a healthy lifestyle and having regular eye examinations goes a long way towards visual health.