In one study, 60 people, average age 75, with mild to moderate AMD, either took 8 mg of zeaxanthin per day alone, with 9 mg of lutein, or lutein alone.
After one year, those taking zeaxanthin could read 1.5 more lines on a standard eye chart and had lost all blind spots. Those who took lutein could better detect subtle contrasts and recover from glare faster.
Doctors concluded that zeaxanthin improves high-contrast vision, and lutein improves low-contrast vision and glare recovery in AMD.