A randomized controlled trial found that supplementation with lutein and zeaxanthin (24 mg daily) significantly improved macular pigment optical density, visual performance, eye strain, eye fatigue, headache frequency, and sleep quality.

Lutein and zeaxanthin are two carotenoids that are found in plants and are particularly high in kale. They accumulate in the rods and cones in the eye and play a major role in preventing macular degeneration.

The study was a 6-month randomized, double-blind, placebo-controlled supplementation trial with 48 healthy, young adults with screen time exposure of at least 6 hours daily. Subjects were evaluated at baseline, 3-months, and 6-months.