Eyesight or vision is the ability to interpret the surrounding environment using reflected light. For having a functional vision, integrity of the eyes and neural pathway behind it is necessary which converts the visible light to electrical signals which are then transmitted to the brain. Light is refracted (bend) at the surface of cornea (which is the transparent lining at the front of the eye) and lens which then passes through the eye and undergoes conversion to electrical signals at the retina which are then transmitted by the optic nerve to the brain which decodes the signal to perception of vision.
Eyesight is most commonly objectively measured in terms of visual acuity which relates to the sharpness of vision. It is measured by Snellen Chart which is a chart containing letters/numerical/symbols in decreasing order of size. A normal visual acuity is expressed as 6/6 (or 20/20). It means that visual acuity is sufficient to clearly see at a distance of 6 meters (or 20 feet).Other parameters to measure eyesight includes near vision (reading), color vision.
Well, in this article we have discussed some of the common causes and symptoms which describes that a person may be suffering from a poor eyesight. Next, we have describes some of the best ways which may help an affected person to improve his/her eye vision.
Common causes and symptoms of poor eyesight are:
1. Myopia /Nearsightedness – Blurry vision when looking at distant objects
2. Hypermetropia /Farsightedness – Blurry vision when reading
3. Cataract – Painless and gradual diminution of vision due to opacity of lens
4 Glaucoma – Usually associated with pain/discomfort in eye
5. Colour Blindness – Difficulty in making out shades of light.
Preventable causes of poor eyesight are:
1. Straining the eyes.
2. Eye Fatigue – reading for a long time without adequate rest in between
3. Poor diet/nutritional deficiency
4. Poor general health
Measures to prevent poor eyesight:
Poor eyesight can be prevented if adequate and necessary behavioral changes are made. Most common eye problems can be tackled if appropriate measures are taken well in time.
1. Eat a lot of fresh fruits. These are a rich source of vitamins and minerals and are the best way for consistent quality eyesight.
2. Include a considerable amount of green leafy vegetables in your diet. Green leafy vegetables are a good source of vitamins especially dark leafy vegetables are good source of vitamin A which helps to prevent night blindness
3. Make a habit to blink regularly. This helps to wet the surface of the eyeball with tear fluid which is continuously formed and thus helps to prevent abrasions at the surface of the cornea.
4. For people who eat nonvegetarian diet, include fish regularly in your diet. Fish and cod liver oil are abundant sources of vitamin A and D which helps to maintain the health of the retina and the rod cells.
5. When reading for a long time or studying, try to take a break regularly usually every 20-30 minutes. This provides rest to the muscles of the eye which prevents eye strain.
6. Wear sunglasses. This helps protect the eye from exposure to ultraviolet rays which is a known risk factor for the formation of cataract.
7. When working on computer screens:
(i) Keep the eyes at the level of the monitor screen
(ii) Use a comfortable chair
(iii) Rest eyes by looking away from the screen every 20 minutes. Take a rest from work every 2 hours.
8. When reading, do so in a well-lit room. Make sure the light is directed towards the book being read.
9. Undergo periodic eyesight examinations so that the problem can be identified early and appropriate measures can be taken well in time to prevent any deterioration or complication. These can be taken every 2-3 yrs in young adult and yearly in people above the age of 50 yrs or those already wearing spectacles or suffering from diagnosed eye ailments.
10. Maintain a healthy lifestyle. Quit smoking as it is a known risk factor associated with retinal macular degeneration.
11. Wear protective eye gears when employed in hazardous jobs
With these healthy habits, it is possible to maintain a good ocular health and prevent poor eyesight.