In 2012, actress Dame Judi Dench told the press that her eyesight was failing and she was unable to read her scripts. The solution? Her daughter and her agent would help her learn lines.

Now in her mid-80s, Dame Judy had been diagnosed with age-related macular degeneration (AMD), a common eye disorder that can cause blindness.

By 2020, it's estimated that around 3 million older Americans will have to contend with this condition.

But AMD isn't the only vision problem that can develop as you get older. The most common are glaucoma, diabetic retinopathy, and cataracts.

More than 6 million Americans over age 65 have some type of vision problem. That's why it's important to take steps at every age to protect your eyes. Here are a few good ones:

• Eat eye-friendly foods that are rich in nutrients such as beta carotene, lutein, zeaxanthin, omega-3 fatty acids, and zinc. That means plenty of orange vegetables such as sweet potatoes, carrots, and squash, as well as cooked tomatoes. Opt for dark leafy greens, berries, nuts and seeds, brown rice, and citrus, which also are high in vitamins A, C, D and E. And enjoy fatty fish like ocean trout and salmon.

• Quit smoking or never start. It's linked to an increased risk of AMD, cataracts, and optic nerve damage.

• Use sunglasses. Find ones that block out 99 to 100 percent of UV-A and UV-B radiation.

• Don't do digital damage. Break up computer and screen time. Try the 20-20-20 rule: Every 20 minutes look about 20 feet in front of you for 20 seconds.