Here’s news anyone with vision problems will be glad to see: A new study has confirmed the first effective treatment for age-related macular degeneration (AMD), the most common cause of vision loss in this country.

In the first clinical trial of its kind, 30 adults with AMD who took lutein supplements for one year were able to see the equivalent of one more line on a standard vision test chart than they had before. (Another 30 in a placebo group got worse.) A third group slightly edged out the lutein-only takers by also downing a multivitamin with other nutrients that have shown promise in treating AMD, including zinc and vitamins A, C, and E.

Earlier studies suggested that eating lutein-rich foods could help prevent AMD, but this was the first to actually compare people taking a supplement with those who didn’t—and focus on treatment. Larger studies still need to be done, the researchers say, but anyone with AMD or who’s worried about getting it— which basically means any person of advancing age—would do well to stock up on lutein. The study used 10-milligram supplements, but you’ll easily hit that number if you make like Popeye and eat even one serving of spinach a day.