There are many lifestyle factors that can affect ocular health such as UV light, alcohol, diet, however smoking is one of the most important factors to control as it can lead to several eye problems. Most common eye problems associated with smoking include age related macular degeneration, cataracts, dry eye, optic neuritis, diabetic retinopathy and glaucoma.
Effects of Smoking
One problem that smoking can cause is dry eye which is when tears are not able to provide sufficient lubrication for your eyes. Smoking with dry eye will make your eyes more likely to be scratchy, burn or red. This is because the conjunctival mucosa is highly sensitive to airborne chemicals, fumes, and irritative gases that originate in tobacco smoke, leading to conjunctival redness, excessive lacrimation and discomfort due to stimulation of the conjunctival-free nerve endings (Yoon, Song and Seo, 2005). Smoking also increases the risk of getting cataracts which is clouding of your eye’s naturally clear lens which causes blurred vision and makes colours look dull and faded. This is due to heavy metals such as cadmium, lead and copper found in tobacco smoke which can collect in the lens causing the formation of cataracts (Schmeling, Gaynes and Tidow-Kebritchi, 2014). In addition, cigarette smoking is an established risk factor for nuclear cataract, there is growing epidemiologic evidence that smoking is also a risk factor for posterior subcapsular cataract and it has been shown to be a risk factor for many common and severe eye diseases, such as age-related macular degeneration, glaucoma, and cataract, which can lead to irreversible blindness (Krishnaiah et al., 2005).
Additionally, the risk of age-related macular degeneration is increased whilst smoking which is when the center of the retina called the macula is damaged leading you to lose your central vision and not being able to see fine detail which is needed for everyday tasks such as reading and driving, however your peripheral vision stays the same. Macular degeneration also causes blind spots and often severely impairs central vision (Bressler, Bressler and Fine, 1988). In addition, increased oxidative stress due to smoking has already been implicated as a causal factor in the pathogenesis of some smoking-related illnesses, such as cataracts, diabetic retinopathy and age related macular degeneration (Hammond, Wooten and Snodderly, 1996). Oxidative stress is essentially an imbalance between the production of free radicals and the ability of the body to counteract or detoxify their harmful effects through neutralization by antioxidants which reduces the amount of oxygen that reaches your macula (Bailey et al., 2004). Antioxidants help maintain lens transparency, so smoking may interfere with the protection from antioxidative nutrients (Kelly et al., 2005). Oxidative stress in the retinal pigment epithelium may contribute to macular degeneration (Bailey et al., 2004).
Another problem that can arise due to smoking is optic neuritis. This occurs when the nerve fibres in the optic nerve which carry messages from the eye to the brain become inflamed therefore leading to damage in vision and smoking increases the risk of optic neuritis due to the lack of oxygen caused by carbon monoxide inhaled from tobacco smoke (Toosy, Mason and Miller, 2014). Furthermore, smokers are insulin resistant exhibiting several aspects of the insulin resistance syndrome so are at an increased risk for type 2 diabetes, consequently cigarette smoking increases the risk for diabetic retinopathy, which is when blood vessels in the eye are damaged causing blurry or distorted vision, due to its metabolic effects in combination with increased inflammation and endothelial dysfunction (Eliasson, 2003). Another common eye problem associated with smoking is glaucoma where the optic nerve, which connects the eye to the brain, becomes damaged. This is usually triggered by a large build up of fluid in the front part of the eye which causes the pressure inside the eye to rise and eventually can lead to vision loss if it isn’t detected and treated in its early stages. Primary open-angle glaucoma is a progressive optic neuropathy and the most common form of glaucoma as the disease is treatable and the visual impairment caused by glaucoma is irreversible so early detection is vital which depends on examination of the optic disc, retinal nerve fibre layer, and visual field in which the drainage angle for fluid within the eye remains open, then there are less common types including closed-angle glaucoma and normal-tension glaucoma (Weinreb and Khaw, 2004). Two relatively recent, large studies (including one prospective cohort study) investigating the effect of smoking have found a significant increase in risk of POAG (Primary Open-Angle Glaucoma) in very heavy smokers, the evidence for a link between current smoking and POAG appears stronger than that of past smoking, but recent studies suggest that heavy smoking may increase the risk of POAG. (Jain, Jain, Abdull and Bastawrous, 2016).
Overall, smoking is an important factor in ocular health in which many studies have indicated a role for smoking in the incidence and progression of age-related macular degeneration (Solberg, Rosner and Belkin, 1998). Smoking is also regularly linked with nuclear cataract however some studies suggest data on smoking and glaucoma, diabetic retinopathy and dry eye are inconclusive (Solberg, Rosner and Belkin, 1998), therefore contradicting other studies signifying that smoking increases the risk of these diseases.
Methods to prevent eye problems
Protecting your eyesight is one of the most essential things you can do to help preserve your quality of life. The foremost causes of blindness and low vision are the eye problems illustrated above. Hence there are many ways to help prevent these ocular diseases from arising such as checking if you are at a higher risk for eye diseases by checking your family’s health history for certain traits like diabetes or high blood pressure. Having said this, have regular physical tests to check for diabetes and high blood pressure due to the fact that if left untreated, diabetes and high blood pressure particularly can lead to vision loss from macular degeneration and diabetic retinopathy. Look for warning signs of changes in vision such as double vision and having difficulties seeing in low light conditions. Also, check for frequent red eyes, floaters and swelling as these can be symptoms for potential eye problems. Exercising more regularly and eating a healthy balanced diet is also important as research has shown that antioxidants can potentially reduce the risk of cataracts (Kelly et al., 2005), which can be attained from eating a lot of fruit and vegetables. Moreover, try to have an eye exam every year as this can determine your risk of getting eye diseases and most importantly don’t smoke.
In conclusion, pursuing these instructions will not guarantee you perfect vision throughout your whole life. However, sustaining a healthy lifestyle and having consistent eye tests will undoubtedly lower the risk of developing major eye problems.
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- Krishnaiah, S., Vilas, K., Shamanna, B., Rao, G., Thomas, R. and Balasubramanian, D., 2005. Smoking and Its Association with Cataract: Results of the Andhra Pradesh Eye Disease Study from India. Investigative Opthalmology & Visual Science, 46(1), p.58.
- Weinreb, R. and Khaw, P., 2004. Primary open-angle glaucoma. The Lancet, 363(9422), pp.1711-1720.
- Jain, V., Jain, M., Abdull, M. and Bastawrous, A., 2016. The association between cigarette smoking and primary open-angle glaucoma: a systematic review. International Ophthalmology, 37(1), pp.291-301.