Lutein

Lutein enters outer-macular pigment, absorbs short-wavelength blue light, and locally terminates lipid peroxidation. Eye-health trials often pair it with zeaxanthin and watch macular pigment optical density and contrast sensitivity. Dark leafy greens are the everyday source; esterified or free forms can both enter this deposition path. People with long screen time or nighttime glare usually see pigment density change only after several months.

Spinach and kale embed lutein in chloroplast lipid membranes; after small-intestinal absorption, lipoproteins carry it to the retina. When macular pigment rises, daytime glare and visual-fatigue scores sometimes improve together. It converts to retinol almost not at all; its role is a macular optical filter. People adding leafy-green pigment to eye nutrition usually assess macular density and reading comfort.