Answer to Question 1
C
Answer to Question 2
Oxidative stress appears to play a significant role in the development of cataracts, but supplements of the antioxidant nutrients (vitamin C, vitamin E, and carotenoids) do not seem to prevent or slow the progression. By comparison, a healthy diet that includes plenty of fruits and vegetables rich in these antioxidant nutrients does seem to slow the progression or reduce the risk of developing cataracts. Vitamin C supplements in high doses (1000 milligrams) and long duration (several years) may increase the risk of cataracts. One other diet-related factor may play a role in the development of cataracts- obesity. Risk factors that typically accompany obesity, such as inactivity, diabetes, or hypertension, do not explain the association. The leading cause of visual loss among older people is age-related macular degeneration, a deterioration of the macular region of the retina. As with cataracts, risk factors for age-related macular degeneration include oxidative stress from sunlight. Preventive factors may include supplements of the omega-3 fatty acids, some B vitamins (folate, vitamin B6, and vitamin B12), antioxidants, zinc, and the carotenoids lutein and zeaxanthin.