What do John Goodman, Ella Fitzgerald, Bono, and Stephen King have in common? They all have contended with vision problems: Goodman with cataracts; Fitzgerald with diabetic retinopathy; Bono with glaucoma; and Stephen King with age-related macular degeneration.

These four conditions are the most common causes of serious vision problems in older Americans. Fortunately, there are steps you can take that can help prevent or slow them, and preserve your eyesight:

• Cataracts. To keep sunlight from damaging your eyes' lenses, wear sunglasses that block out 99% to 100% of UV-A and UV-B radiation.

• Glaucoma. Research from UCLA shows that 30 minutes of exercise a day lowers the risk of glaucoma by 73%.

• Diabetic retinopathy. Harvard Health says normalizing your blood glucose levels can reduce the risk of diabetic retinopathy by 75%.

• Age-related macular degeneration. Taking 500 mg of vitamin C; 400 IU of vitamin E; 10 mg of lutein, 2 mg of zeaxanthin, 80 mg of zinc oxide, and 2 mg of copper (cupric oxide) may help prevent or slow progression of the disease when combined with a healthy, plant-based diet.

And, for overall eye health:

1. Make sure your diet contains dark, leafy greens like spinach and omega-3-rich salmon and flaxseed or take 900 mg of DHA supplements daily.

2. See an ophthalmologist for a comprehensive dilated eye exam annually.

3. Maintain a healthy weight — being overweight increases your risk for systemic conditions such as diabetes that may lead to retinopathy and glaucoma.

4. Don't smoke or vape. Research shows that smoking and vaping increases your risk of AMD and cataracts, as well as plus optic nerve damage.