Quick Summary
What did CL's tests of vision supplements show?
Our tests showed that all products contained the lutein and zeaxanthin they claimed within a reasonable margin (ranging from 6.1 mg to 30.8 mg of lutein and 1.3 mg to 6.7 mg of lutein per daily serving), with many providing more than listed. The additional amounts, or overages, are likely added to assure that products continue provide the claimed amounts throughout their shelf lives because lutein and zeaxanthin can degrade over time (see What CL Found and How Products Were Evaluated).
The cost to obtain 10 mg of lutein from each product ranged from just 6 cents to 69 cents, meaning that you could pay 12 times as much to get the same amount of lutein from one product as from another. Higher-cost products tended to include additional ingredients.
Which vision supplements with lutein and zeaxanthin products are best?
Based on our test results, product ingredients and formulas, supporting clinical evidence, and value, we chose a Top Pick lutein/zeaxanthin supplement, a Top Pick AREDS supplement, and a Top Pick supplement for dry eyes.
What are lutein and zeaxanthin?
Lutein and zeaxanthin are antioxidant pigments found in the macula of the eye (in the retina) and are believed to protect the macula from damage (see What It Is). 
What are the health benefits of lutein and zeaxanthin?
On average, people don't consume enough lutein and zeaxanthin in their diets and/or have low levels of lutein in their blood or low macular pigment density; for them, taking a lutein supplement may slow the progression of age-related macular degeneration (AMD), although it won't improve the condition. It may also reduce the risk of needing cataract surgery and improve some aspects of brain function (see What It Does).
AREDS:
Other ingredients, particularly zinc and vitamin C, may provide additional benefits in slowing the progression of age-related macular degeneration (see AREDS). Three formulas with these ingredients were tested and reviewed: Bausch & Lomb PreserVision AREDS2, Bausch & Lomb PreserVision AREDS3, and VITEYES AREDS2 Classic. In addition, we tested these vision supplements: Bausch + Lomb Blink NutriTears, Bausch + Lomb Ocuvite Adult 50+, Life Extension MacuGuard, NOW Lutein & Zeaxanthin, Pure Encapsulations Lutein/Zeaxanthin, Swanson Synergistic Eye Health, and Trunature (Costco) Vision Complex Lutein & Zeaxanthin. (Be aware of unnecessarily high doses of zinc in some vision formulas, which can potentially cause adverse effects, including anemia -- see Concerns and Cautions).
How much lutein and zeaxanthin should I take?
If you already eat more than half a cup a day of green leafy vegetables (which naturally provide lutein and zeaxanthin), you can probably skip a supplement. If you get some greens but perhaps not enough, a supplement with at least 6 to 10 mg of lutein + zeaxanthin could help. If you don't eat green leafy vegetables, 10 mg would seem more appropriate and even 20 mg may be helpful and still safe (see Dosage).
To enhance absorption, it is best to take lutein and zeaxanthin supplements with a fatty meal but be aware that consumption of certain foods and supplements may decrease absorption of lutein and zeaxanthin (see Concerns and Cautions). In addition, try to eat at least one orange per week and have fish at least once a week, as these are also associated with a reduced risk of AMD.
