A new study has warned that smoking over 20 cigarettes a day can cause blindness. Chronic tobacco smoking can have harmful effects on spatial and colour vision.
India Today Web Desk
Smoking 20 cigarettes a day can make you go blind.
While excessive smoking has been linked to various health issues, including heart disease and cancer, a new study has warned that smoking over 20 cigarettes a day can cause blindness.
The study from Rutgers University noted that chronic tobacco smoking can have harmful effects on spatial and colour vision.
Previous studies have also pointed to long-term smoking as doubling the risk for age-related macular degeneration and as a factor causing lens yellowing and inflammation.
- For the study, the team looked at 71 healthy people who smoked less than 15 cigarettes in their entire lives and 63 people who smoked over 20 cigarettes a day, were diagnosed with tobacco addiction and reported no attempts to stop smoking.
- The participants were between the ages of 25 and 45 and had a normal or corrected-to-normal vision as measured by standard visual acuity charts.
- The researchers looked at how participants discriminated contrast levels (subtle differences in shading) and colors while seated 59 inches from a 19-inch cathode-ray tube monitor that displayed stimuli, while researchers monitored both eyes simultaneously.
The findings, published in the journal ‘Psychiatry Research,’ noted significant changes in the smokers’ red-green and blue-yellow colour vision. This suggests that consuming substances with neurotoxic chemicals, such as those in cigarettes, may cause overall colour vision loss.
Heavy smokers also have reduced ability to discriminate contrasts and colours compared with non-smokers.
“Our results indicate excessive use of cigarettes, or chronic exposure to their compounds, affects visual discrimination, supporting the existence of overall deficits in visual processing with tobacco addiction,” said co-author Steven Silverstein, director of research at Rutgers University Behavioral Health Care.
“Cigarette smoke consists of numerous compounds that are harmful, and it has been linked to a reduction in the thickness of layers in the brain, and to brain lesions, involving areas such as the frontal lobe, which plays a role in voluntary movement and control of thinking, and a decrease in activity in the area of the brain that processes vision,” he said.
Although the research did not give a physiological explanation for the results, Silverstein said that since nicotine and smoking harm the vascular system, the study suggests they also damage blood vessels and neurons in the retina.
- Age Related Macular Degeneration (AMD)
AMD begins as a loss of central vision which makes it difficult to read and see fine details. Over time, vision loss increases significantly. Of the two types of AMD, dry and wet, dry AMD is the most common.
Vision loss in dry AMD usually gets worse slowly. In wet AMD, tiny blood vessels under the retina leak or break open. This changes vision and causes scar tissue to form. Wet AMD is less common, but more quickly harmful to vision.
Glaucoma causes a gradual break down of the cells that make up the nerve in your eye that sends visual information to your brain (optic nerve).
As the nerve cells die, vision is slowly lost, usually beginning with side vision. Often the loss of vision is not noticeable until a large amount of nerve damage has occurred. This is the reason why as many as half of all people with glaucoma may be unaware that they have it.
Cataract is a clouding of the eye’s naturally clear lens. It usually gets worse as we get older. Most cataracts are related to aging.
- Diabetic retinopathy
Diabetic retinopathy is a common complication of diabetes. It affects the tiny blood vessels of the retina in the eye.
Retinal blood vessels can break down, leak or become blocked and this can affect vision over time.
In some people with diabetic retinopathy, serious damage to the eye can occur when new blood vessels grow on the surface of the retina.
- Dry Eye Syndrome
Dry Eye Syndrome is an eye disease that appears as damaged blood vessels in the eye. This can lead to eye irritation, itchy and scratchy eyes, and burning sensation of the eyes.