Can smoking cause blindness
Smoking harms almost every organ in the body including the heart and the eye and it is the single most common preventable cause of diseases and premature death in the world.
Does smoking cause cataracts
Cataracts is opacity of the natural lens inside the eye. The condition is age related and develops mainly in aged group (60s and above). The opacity increased gradually and slowly over years. However, in smokers, there will be acceleration of the development of cataract due to accumulation of heavy metals found in tobacco smoke inside the natural lens such as lead, cadmium and copper.
People who smoke more than 20 cigarettes per day are twice as likely to develop cataract compared to non-smokers. Thus, smoker can undergo cataract surgery at younger age compared to non-smokers.
Smoking and Macular Degeneration
Studies showed that smokers are three times more likely to develop Age Related Macular Degeneration (AMD) compared with people who have never smoked and other studies showed this relationship is dose dependent which means the more you smoke, the more likely you will develop AMD.
In addition, female smokers are 5.5 times more likely to develop AMD than non-smokers. Many studies showed that quitting smoking can significantly reduce the risk of developing AMD even if you stop smoking later in life.
Smoking and Uveitis
Uveitis means an inflammation of the dark middle layer of the eye and it is a serious disease that can cause many complications such as cataract, glaucoma and retinal detachment complete vision loss, for that the patient can end up with permanent visual loss and blindness. Smokers have high risk with 2.2 times more than non-smokers to develop uveitis.
Smoking and Diabetic Retinopathy
Smokers have higher risk to develop diabetes as well as the development and progression of diabetic retinopathy. This is how smoking do that:
1- Increase blood sugar in diabetic patient.
2- Increase blood pressure which can have negative impact on retinal blood vessels in patients with diabetic retinopathy.
3- Increase blood carbon monoxide and reduce oxygen supply to the eye.
4- Tobacco smoke contains free radicals that cause oxidative damage to the retina and also reduce the protective antioxidants.
Smoking and retinal vein occlusion
Smoking increase the risk of retinal vein occlusion by:
1- Carbon monoxide and nicotine accelerate atherosclerosis with fatty deposits in the blood vessels.
2- Induce blood clotting by increasing platelet aggregation.
Smoking and Dry Eyes
Smokers and even second hand smokers are nearly twice as likely to develop dry eye syndrome compared to non-smokers. Tobacco smoke can cause irritation to the cornea and conjunctiva with dryness to contact lens wearer.
Does smoking cause glaucoma
Smokers are at high risk to develop high intraocular pressure later in life. Chronic high intraocular pressure can lead to damage to optic nerve and cause glaucoma. Some studies found that this relation is dose dependent, the more you smoke, the higher the risk to develop glaucoma and also the higher the risk of glaucoma progression.
Tobacco optic neuropathy
This is one form of toxic/nutritional optic neuropathy which can affect both optic nerves and it can also be called as tobacco-alcohol optic neuropathy or tobacco-alcohol amblyopia. Chronic exposure to alcohol and tobacco can cause damage to optic nerve.
Cyanide in tobacco can cause demyelination of optic nerve and also impair the mitochondrial oxidative phosphorylation of the nerve
Smoking and Pregnancy
Pregnant women who smoke during pregnancy are at increased risk of many fetal eye disorders and here are some of these disorders:
1- Give premature birth. Premature birth increases the risk retinopathy of premature which can cause permanent vision loss. In addition, the severity of retinopathy is higher in pregnant smoker than nonsmoker.
2- High incidence of crossed eye or strabismus especially esotropia or inward turn of the eye.
3- Refractive errors that can appear earlier or later in life such as hyperopia, myopia, astigmatism and anisometropia. Early uncorrected refractive errors can cause amblyopia.
4- Higher risk of Optic nerve hypoplasia.
5- increase the risk of anophthalmia and microphthalmia in children.
6- increased risk of eyelid edema at 6 weeks after birth.