Bilberry extract has been studied for its relationship to night vision and contrast sensitivity — the kind of vision that matters most when you're driving after dark or adjusting between light and shadow.
Lutein and zeaxanthin are carotenoids that accumulate naturally in the macula, the part of the eye responsible for sharp central vision. Research published in ophthalmology journals has linked healthy levels of these two nutrients to macular pigment density and visual function.
None of this means a supplement will "fix" your eyes overnight — nutrition doesn't work that way, for eyes or anything else. What the research does suggest is that consistent daily intake of these specific nutrients may help support the eye's natural processes over time, especially when your diet doesn't already include much of them.