Eye Health Supplements

01Luteinhuman trials

the guide

the macula's main yellow pigment, with zeaxanthin: a Florida group identified the human macular pigment as lutein and zeaxanthin in 1985 (Bone 1985), and in donor retinas lutein outnumbered zeaxanthin toward the edge of the retina while zeaxanthin led at the center (Bone 1988).

evidence: the anchor human trial is AREDS2. it enrolled 4,203 people aged 50 to 85 with large drusen in both eyes, or large drusen in one eye and advanced age-related macular degeneration in the other, asked them to take the AREDS vitamin and zinc formula or a variant of it, and randomized them to lutein with zeaxanthin, fish oils, both, or placebo for a median of five years (AREDS2 2013). adding lutein and zeaxanthin did not significantly reduce progression to advanced disease in the primary analysis. in exploratory comparisons the pair did better than the beta-carotene it replaced (AREDS2 report 3, 2014), and the ten-year follow-up kept that direction (AREDS2 report 28, 2022). a 2023 Cochrane review rated the evidence for lutein and zeaxanthin against placebo as low certainty, with similar or slightly lower risk of progression (Evans 2023). across 20 trials, supplements raised macular pigment density in patients and in healthy people (Ma 2016), and in 115 healthy young adults a year of the pair improved recovery from a bright flash and color contrast but not glare disability, in a trial where three of the five authors worked for DSM Nutritional Products (Hammond 2014).

watch for: AREDS2 tested lutein and zeaxanthin in place of beta-carotene because beta-carotene had raised lung cancer risk in smokers and former smokers and because the pair is part of the retina (AREDS2 report 3, 2014); in the trial more lung cancers appeared with beta-carotene, mostly in former smokers (AREDS2 2013), and at ten years beta-carotene nearly doubled the odds while lutein and zeaxanthin showed no significant rise (AREDS2 report 28, 2022). more is not always better: a woman in her sixties who had taken a lutein supplement for eight years on top of a very high-lutein diet developed glistening crystals in both foveas, without vision loss, and they began to clear in one eye after she stopped (Choi 2016). a rise in macular pigment density is a measurement, not proof that eye disease was prevented.

02Zeaxanthinhuman trials, mostly with lutein

the guide

the other macular carotenoid, concentrated at the center: in donor retinas, zeaxanthin outnumbered lutein about 2.4 to 1 in the central quarter millimeter, and the ratio reversed toward the edge (Bone 1988). part of the central pigment is meso-zeaxanthin, which the Florida group proposed the retina makes from lutein (Bone 1997).

evidence: every large trial gave it with lutein, so its own effect has not been separated: AREDS2 tested lutein plus zeaxanthin as one arm (AREDS2 2013). the trials that gave zeaxanthin alone are small. in a year-long trial of 60 patients with early atrophic macular degeneration, 57 of them men, the control arm took lutein rather than a placebo, and macular pigment rose in all three arms with no difference between them (Richer 2011); high-contrast acuity improved by 1.5 lines in the zeaxanthin arm, while the lutein arm did better on low-contrast acuity, contrast sensitivity and glare recovery. in eight people with macular telangiectasia type 2 given zeaxanthin alone for two years, macular pigment rose around the fovea but no objective gain in vision was found (Choi 2017).

watch for: zeaxanthin's safety record in AREDS2 is the pair's record, since the trial never gave it alone (AREDS2 2013; AREDS2 report 28, 2022). in the two-year trial of zeaxanthin alone in macular telangiectasia, one woman developed crystals in the macula, with no change in visual acuity, and they cleared several months after she stopped (Choi 2017). the year-long zeaxanthin trial ran at a veterans' health care facility, enrolled almost only men, and had no placebo arm (Richer 2011).

03Astaxanthinsmall human trials, mostly company-run

the guide

a red carotenoid from microalgae and seafood (EFSA 2020), sold for the eyes but not part of the macular pigment, which is lutein, zeaxanthin and meso-zeaxanthin (Bone 1985; Bone 1997). its eye claims rest on blood flow and eye-strain measures, not on pigment.

evidence: small trials, most of them short and most run by companies or given in mixes. in 20 healthy volunteers, blood flow velocity in the choroid under the macula rose after four weeks compared with each person's own starting value, with no change on placebo; the abstract reports changes within each arm, not a comparison between arms (Saito 2012). in 64 children aged 10 to 14 with heavy screen use, an astaxanthin capsule beat placebo on an eye-strain questionnaire over 84 days but not on focusing distance, visual acuity or a tear test; seven of the 12 authors list AstaReal, the brand tested, or Fuji Chemical Industries as their employer (Hecht 2025). the longest eye trial gave astaxanthin only inside a mix with lutein, zeaxanthin and other antioxidants: in 145 people with age-related macular degeneration, those given the mix had better visual acuity at two years than those given no supplement, in an open-label trial (Piermarocchi 2012).

watch for: EU food-safety experts found astaxanthin from supplements, at the level they assessed, plus a normal diet within their acceptable daily intake for adults but over it for children aged 10 to 13 (EFSA 2020), and EFSA's 2025 opinions on astaxanthin in foods hold only if children and adolescents do not take astaxanthin supplements on the same day (EFSA 2025). apart from eye-strain trials, the only study we found that gave astaxanthin on its own to people with an eye disease and followed the disease itself had no comparison group: 60 middle-aged and older adults with mild to moderate dry eye improved on symptom and tear-film scores over a month (Tian 2022).

04Citicoline (CDP-choline)small human trials, mostly glaucoma

the guide

CDP-choline, an intermediate the body uses to build phosphatidylcholine for cell membranes; swallowed, it releases cytidine and choline (Secades 2006, a review whose first author worked in the medical department of the drug company Grupo Ferrer). it is approved in some countries as a stroke drug (Davalos 2012), and eye researchers test it as a protector of the retinal ganglion cells, the neurons that connect the eye to the brain and die in glaucoma (Prinz 2023).

evidence: small glaucoma trials, most from eye clinics in Rome and Milan, using injections, an oral solution and eye drops. a Rome group reported better retinal and visual-cortex electrical responses after citicoline injections into muscle in 40 patients (Parisi 1999) and after eye drops or an oral solution in later small trials (Parisi 2015; Parisi 2026). in a three-year placebo-controlled trial of citicoline eye drops in 80 patients, 40 in each arm, loss on the standard 24-2 visual field test did not differ significantly, while loss on the central 10-2 field and in nerve fiber thickness was slower on citicoline; the eye-drop maker co-funded the trial and the authors called it a pilot (Rossetti 2020). a 2023 systematic review of 10 studies and 424 patients found no difference from controls in eye pressure, visual field, nerve fiber layer or retinal electrical response (Prinz 2023).

watch for: the forms differ: the trials used injections, an oral solution and eye drops, not only the capsules sold as supplements. a phase 3 trial of citicoline eye drops, sponsored by their maker Omikron Italia, plans 1,000 patients and listed no results when read on 25 October 2026 (NCT05710198). outside the eye, two large citicoline trials found no benefit: 2,298 people after stroke, with no difference in safety measures from placebo (Davalos 2012), and 1,213 people after brain injury (Zafonte 2012).

the Eye Health Supplements bench sets lutein and zeaxanthin, the pair the AREDS2 trial tested, beside astaxanthin and citicoline. AREDS2 tested lutein with zeaxanthin in 4,203 people aged 50 to 85 who already had intermediate age-related macular degeneration, or advanced disease in one eye, so its results describe them, not healthy eyes. the bench gives no amounts and no timing. the Eye Health Supplements bench covers 4 compounds: Lutein, Zeaxanthin, Astaxanthin, Citicoline (CDP-choline).