|Eye colour -Wikipedia|
Those with high blood sugar, those who take steroids, people with heavy metal poisoning, people using hair dyes, smokers. and lack of vitamins. People with early cataract may benefit from new eyeglasses, bright lighting, anti-glare sunglasses, or magnifying lenses. If, despite such devices, cataract interferes with daily activities, surgery is the only effective treatment. Cataract surgery, which is common, involves removal of the cloudy lens and replacement with an artificial lens.
Eyes exercise can help your sight immensely. When looking an an object circle it with . yours eyes before focusing on it.
When yo work close up such as with computers at various intervals focus your eyes on far away objects.
Try looking diagonaly with your eyes on the floor and up to the sky.