One of the two yellow pigments that sit in the centre of your retina.
Retina ClearIn plain words
Lutein is a carotenoid, a plant pigment you get from kale, spinach, corn and egg yolk. After you eat it, it travels to the macula, the patch of retina you read with, where it builds up as a yellow screen.
Retina ClearWhat the evidence shows
The large AREDS2 trial gave people with existing macular degeneration 10 mg of lutein plus 2 mg of zeaxanthin. Overall it matched the older formula, and the pair proved a safer swap for beta-carotene. In healthy people, higher intake reliably raises macular pigment, but proof that this sharpens everyday sight is thin.
In this capsule
Lutein is on the seller's list, and no amount is given, so you cannot tell whether a capsule comes anywhere near 10 mg.
Common question
Is 10 mg the standard lutein dose?
It is the dose used in AREDS2, so it is the number researchers quote. Whether any product delivers it depends on what its label prints.