Life Extension Magazine®

Woman taking vision test for macular degeneration

Improve Visual Acuity

Ingestion of plant carotenoids can lower risk of advanced macular degeneration by 41%. The addition of the spice saffron improves visual acuity as measured on a standard eye chart.

Scientifically reviewed by Dr. Gary Gonzalez, MD, in August 2023. Written by: Michael Downey, Health & Wellness Author.

Macular degeneration is the leading cause of irreversible vision loss in older adults.1

It happens when the macula loses structural density. The result is blinding damage to the light-sensing retina of the eye.

Primary culprits like smoking and exposure to ultraviolet sunrays can be controlled.2-4 But the single, largest factor in its development is aging.5

Specific plant carotenoids have been shown to protect the macula from UV-light damage and oxidation.6-10

Individuals with the highest levels of the carotenoids lutein and zeaxanthin show a striking 41% lower risk of advanced age-related macular degeneration.11

A corroborating study found that saffron improved visual function in macular degeneration patients within three months. This visual enhancement occurred even among those who were already using lutein and zeaxanthin.11

Putting the brakes on macular degeneration and improved vision have been demonstrated in response to several plant-derived nutrients.11-16

Human Eye Anatomy and Macular Degeneration

Lutein and Zeaxanthin

Two of the best-known nutrients that protect against age-related vision loss are lutein and zeaxanthin.11 They’re found in high concentrations in several parts of the eye, including the lens, retina, and macula.17,18

These yellow carotenoids absorb higher-energy (blue and ultraviolet) light, preventing it from damaging retinal tissues. Lutein and zeaxanthin also scavenge free radicals and reduce their damaging impact on retinal cells.17-20

Several clinical trials have demonstrated their effectiveness. One recent study found a reduced risk of end-stage macular degeneration, which often causes blindness, with moderate consumption of eggs — a naturally rich source of lutein and zeaxanthin.21

Other studies of adults with age-related macular degeneration demonstrated that taking 10 to 12 mg of lutein daily raises the density of protective pigmented cells in the retina by up to 175%, compared with patients taking a placebo.12,13 Increased macular density enhances the ability to protect against eye-damaging ultraviolet and blue light.

In patients with early age-related macular degeneration, 48 weeks of supplementation with either lutein alone or lutein combined with zeaxanthin produced significant increases in electroretinogram signals. This is a measure of the power of light-sensitive cells to produce electrical impulses after stimulation by light.14

A series of large, clinical trials demonstrates that lutein and/or zeaxanthin supplementation can improve retinal function, increase the ability to see contrasting colors and shapes, and improve visual acuity (the sharpness of vision at a distance).9,11,13,14,22-24

One study that lasted over 20 years included more than 102,000 people aged 50 and older. It adjusted for factors like cigarette smoking and eating patterns.

After assessing blood levels of carotenoids, scientists found that those with the highest intake of lutein and zeaxanthin had a remarkable 41% lower risk of progressing to advanced macular degeneration. High intake of lutein and zeaxanthin even protected former smokers, who tend to have a much higher incidence of macular degeneration.11


Woman getting eyes checked

The damaging effects of UV light are well known. But chronic exposure to blue light, the kind given off by TVs, smart phones, tablets, and computers, is also associated with increased risk of macular degeneration.25-27

Replenishing the pigments in the eye’s protective layer can quench much of the photochemical damage done by this light. In fact, research shows that progression of macular degeneration can be slowed by regular supplementation with lutein, zeaxanthin, and a third pigment, meso-zeaxanthin.28

Meso-zeaxanthin is a carotenoid needed to maintain the density of pigments in the macula. When young people consume lutein in their diet, it readily converts to meso-zeaxanthin.29

The importance of meso-zeaxanthin is reflected in the composition of macular pigments:

  • Lutein 50%
  • Zeaxanthin 25%
  • Meso-zeaxanthin 25%

People with macular degeneration have 30% less meso-zeaxanthin in their macula compared to those with good eye health.30

When taken as a supplement, meso-zeaxanthin is absorbed into the bloodstream and increases macular pigment levels.8

What you need to know

  • Age-related macular degeneration is the leading cause of vision loss in older adults, and it has no cure.
  • Certain carotenoids protect the macula from harmful UV-light damage and oxidation.
  • Lutein, zeaxanthin, meso-zeaxanthin, astaxanthin, saffron, and alpha-carotene have been identified as key nutrients that can protect the eyes and slow the progression of age-related macular degeneration.
  • Cyanidin-3-glucoside enhances night vision, that can be a problem also affecting those with age-related macular degeneration.


A reddish carotenoid that can be derived from marine algae, astaxanthin helps protect retinal cells from being damaged by oxidative and physical stress.31-33

In experimental studies astaxanthin prevented the vision-damaging effects of wet macular degeneration that occurs when blood vessels leak fluid into the retina. It can also help prevent cell damage related to increased pressure in the eye, a cause of glaucoma.32,34

The benefits of astaxanthin, particularly for diabetics, could be substantial. Among people who have had diabetes for over 10 years, 80% suffer from diabetic retinopathy, that occurs when high levels of blood sugar cause progressive damage to the retina. Rodent studies have demonstrated that astaxanthin prevents early death of nerve cells in the retina, resulting from excess blood sugar.31

Two human studies demonstrated that the combination of astaxanthin, lutein, and zeaxanthin significantly improved visual clarity in patients, compared with those who were untreated.35,36


Woman driving at night

A study published in 2019 found that saffron, a culinary spice derived from the crocus flower, enhances visual function in patients with mild to moderate age-related macular degeneration, including those already supplementing with lutein and zeaxanthin.37

In this study, individuals took 20 mg of saffron or a placebo daily for three months. Subjects who weren’t taking other supplements improved on a standard vision-measuring eye chart by .69 letters, while those already taking lutein or zeaxanthin improved by .73 letters.37

This report validates earlier research demonstrating that, in people with early macular degeneration, saffron improves both visual acuity, and sensitivity of the retina to light.15,16,38

In one study, patients with early age-related macular degeneration took either 20 mg of saffron or a placebo daily. Subjects taking saffron showed stronger electrical responses to light, showing that saffron improved the light-sensing abilities of retinal cells.16

The same study found that saffron-supplemented subjects were able to read one entire additional line on the eye chart after three months, while placebo subjects did not improve. This means that someone whose visual acuity at a distance was 20/40 prior to supplementation, would be able to see with 20/30 vision afterward.16

To determine whether it could produce long-term effects, scientists gave 20 mg of saffron per day to patients with early macular degeneration over an average treatment period of 14 months. Retinal sensitivity remained improved for the entire period, and average visual acuity improved by an astounding two lines on the eye chart, showing that longer supplementation produced even greater improvement.15


Woman smiling after eye exam

Alpha-carotene protects the pigmented cells of the retina from light-induced oxidative damage.

A large study was conducted on 63,443 women and 38,603 men, aged 50 and older. The results showed that people with the highest dietary intake of alpha-carotene had a 32% reduced risk for developing advanced age-related macular degeneration, compared with those with the lowest consumption.11

This yellow-orange carotenoid has even been shown to provide protection for smokers.

In a recent study, scientists evaluated the dietary intake of carotenoids in 1,414 men aged 65 and over and their incidence of age-related macular degeneration. Current smokers who ate the most foods containing alpha-carotene (like pumpkin and carrots) were found to have a significantly reduced risk of developing macular degeneration.39

Protect Against Night Blindness

Many individuals with age-related macular degeneration experience difficulties when performing activities at night and under low light, such as driving or reading at night.40

A flavonoid found in many berries,41,42 cyanidin-3-glucoside enhances the quality and function of rhodopsin, a light-sensitive protein found in the rod cells of the retina, and actually boosts the ability of rhodopsin to regenerate.41,43-45 Rod cells are the eye’s most sensitive cells, allowing us to see in very dim light. Loss of rod cells is associated with night blindness or reduced vision in low light.46

A study of healthy volunteers showed that a berry extract concentrate containing cyanidin-3-glucoside improved night vision, allowing aging individuals to see better in darkness after just 30 minutes.47


Macular degeneration is a major threat to aging individuals.

Several plant compounds have been shown to protect against many of the underlying causes of compromised vision.

Saffron has been shown to provide protection against early macular degeneration.15,16,38

Alpha-carotene can help protect against advanced macular degeneration.11

Supplementing with an array of these plant compounds including lutein, zeaxanthin, and meso-zeaxanthin provides complementary eyesight protection.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.


  1. Available at: Accessed June 24, 2019.
  2. Available at: Accessed June 24, 2019.
  3. Tan JS, Mitchell P, Kifley A, et al. Smoking and the long-term incidence of age-related macular degeneration: the Blue Mountains Eye Study. Arch Ophthalmol. 2007 Aug;125(8):1089-95.
  4. Velilla S, Garcia-Medina JJ, Garcia-Layana A, et al. Smoking and age-related macular degeneration: review and update. J Ophthalmol. 2013;2013:895147.
  5. Wang D, Jiang Y, He M, et al. Disparities in the Global Burden of Age-Related Macular Degeneration: An Analysis of Trends from 1990 to 2015. Curr Eye Res. 2019 Jun;44(6):657-63.
  6. Bian Q, Gao S, Zhou J, et al. Lutein and zeaxanthin supplementation reduces photooxidative damage and modulates the expression of inflammation-related genes in retinal pigment epithelial cells. Free Radic Biol Med. 2012 Sep 15;53(6):1298-307.
  7. Available at: Accessed June 24, 2019.
  8. Bone RA, Landrum JT, Cao Y, et al. Macular pigment response to a supplement containing meso-zeaxanthin, lutein and zeaxanthin. Nutr Metab (Lond). 2007 May 11;4:12.
  9. Richer S, Stiles W, Statkute L, et al. Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry. 2004 Apr;75(4):216-30.
  10. Sabour-Pickett S, Beatty S, Connolly E, et al. Supplementation with three different macular carotenoid formulations in patients with early age-related macular degeneration. Retina. 2014 Sep;34(9):1757-66.
  11. Wu J, Cho E, Willett WC, et al. Intakes of Lutein, Zeaxanthin, and Other Carotenoids and Age-Related Macular Degeneration During 2 Decades of Prospective Follow-up. JAMA Ophthalmol. 2015 Dec;133(12):1415-24.
  12. Garcia-Layana A, Recalde S, Alaman AS, et al. Effects of lutein and docosahexaenoic Acid supplementation on macular pigment optical density in a randomized controlled trial. Nutrients. 2013 Feb 15;5(2):543-51.
  13. Murray IJ, Makridaki M, van der Veen RL, et al. Lutein supplementation over a one-year period in early AMD might have a mild beneficial effect on visual acuity: the CLEAR study. Invest Ophthalmol Vis Sci. 2013 Mar 11;54(3):1781-8.
  14. Ma L, Dou HL, Huang YM, et al. Improvement of retinal function in early age-related macular degeneration after lutein and zeaxanthin supplementation: a randomized, double-masked, placebo-controlled trial. Am J Ophthalmol. 2012 Oct;154(4):625-34 e1.
  15. Piccardi M, Marangoni D, Minnella AM, et al. A longitudinal follow-up study of saffron supplementation in early age-related macular degeneration: sustained benefits to central retinal function. Evid Based Complement Alternat Med. 2012;2012:429124.
  16. Falsini B, Piccardi M, Minnella A, et al. Influence of saffron supplementation on retinal flicker sensitivity in early age-related macular degeneration. Invest Ophthalmol Vis Sci. 2010 Dec;51(12):6118-24.
  17. Ma L, Lin XM. Effects of lutein and zeaxanthin on aspects of eye health. J Sci Food Agric. 2010 Jan 15;90(1):2-12.
  18. Roberts JE, Dennison J. The Photobiology of Lutein and Zeaxanthin in the Eye. J Ophthalmol. 2015;2015:687173.
  19. Aimjongjun S, Sutheerawattananonda M, Limpeanchob N. Silk lutein extract and its combination with vitamin E reduce UVB-mediated oxidative damage to retinal pigment epithelial cells. J Photochem Photobiol B. 2013 Jul 5;124:34-41.
  20. Pongcharoen S, Warnnissorn P, Lertkajornsin O, et al. Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes. Biol Res. 2013;46(1):39-45.
  21. Gopinath B, Liew G, Tang D, et al. Consumption of eggs and the 15-year incidence of age-related macular degeneration. Clin Nutr. 2019 Mar 16.
  22. Ma L, Yan SF, Huang YM, et al. Effect of lutein and zeaxanthin on macular pigment and visual function in patients with early age-related macular degeneration. Ophthalmology. 2012 Nov;119(11):2290-7.
  23. Sasamoto Y, Gomi F, Sawa M, et al. Effect of 1-year lutein supplementation on macular pigment optical density and visual function. Graefes Arch Clin Exp Ophthalmol. 2011 Dec;249(12):1847-54.
  24. Weigert G, Kaya S, Pemp B, et al. Effects of lutein supplementation on macular pigment optical density and visual acuity in patients with age-related macular degeneration. Invest Ophthalmol Vis Sci. 2011 Oct 17;52(11):8174-8.
  25. van der Burght BW, Hansen M, Olsen J, et al. Early changes in gene expression induced by blue light irradiation of A2E-laden retinal pigment epithelial cells. Acta Ophthalmol. 2013 Nov;91(7):e537-45.
  26. Wielgus AR, Collier RJ, Martin E, et al. Blue light induced A2E oxidation in rat eyes--experimental animal model of dry AMD. Photochem Photobiol Sci. 2010 Nov;9(11):1505-12.
  27. Algvere PV, Marshall J, Seregard S. Age-related maculopathy and the impact of blue light hazard. Acta Ophthalmol Scand. 2006 Feb;84(1):4-15.
  28. Lim LS, Mitchell P, Seddon JM, et al. Age-related macular degeneration. Lancet. 2012 May 5;379(9827):1728-38.
  29. Bone RA, Landrum JT, Friedes LM, et al. Distribution of lutein and zeaxanthin stereoisomers in the human retina. Exp Eye Res. 1997 Feb;64(2):211-8.
  30. Quantum Nutritionals, data on file.
  31. Dong LY, Jin J, Lu G, et al. Astaxanthin attenuates the apoptosis of retinal ganglion cells in db/db mice by inhibition of oxidative stress. Mar Drugs. 2013 Mar 21;11(3):960-74.
  32. Izumi-Nagai K, Nagai N, Ohgami K, et al. Inhibition of choroidal neovascularization with an anti-inflammatory carotenoid astaxanthin. Invest Ophthalmol Vis Sci. 2008 Apr;49(4):1679-85.
  33. Li Z, Dong X, Liu H, et al. Astaxanthin protects ARPE-19 cells from oxidative stress via upregulation of Nrf2-regulated phase II enzymes through activation of PI3K/Akt. Mol Vis. 2013;19:1656-66.
  34. Cort A, Ozturk N, Akpinar D, et al. Suppressive effect of astaxanthin on retinal injury induced by elevated intraocular pressure. Regul Toxicol Pharmacol. 2010 Oct;58(1):121-30.
  35. Parisi V, Tedeschi M, Gallinaro G, et al. Carotenoids and antioxidants in age-related maculopathy italian study: multifocal electroretinogram modifications after 1 year. Ophthalmology. 2008 Feb;115(2):324-33 e2.
  36. Piermarocchi S, Saviano S, Parisi V, et al. Carotenoids in Age-related Maculopathy Italian Study (CARMIS): two-year results of a randomized study. Eur J Ophthalmol. 2012 Mar-Apr;22(2):216-25.
  37. Broadhead GK, Grigg JR, McCluskey P, et al. Saffron therapy for the treatment of mild/moderate age-related macular degeneration: a randomised clinical trial. Graefes Arch Clin Exp Ophthalmol. 2019 Jan;257(1):31-40.
  38. Marangoni D, Falsini B, Piccardi M, et al. Functional effect of Saffron supplementation and risk genotypes in early age-related macular degeneration: a preliminary report. J Transl Med. 2013 Sep 25;11:228.
  39. Kim EK, Kim H, Vijayakumar A, et al. Associations between fruit and vegetable, and antioxidant nutrient intake and age-related macular degeneration by smoking status in elderly Korean men. Nutr J. 2017 Dec 4;16(1):77.
  40. Ying G-S, Maguire MG, Liu C, et al. Night vision symptoms and progression of age-related macular degeneration in the Complications of Age-related Macular Degeneration Prevention Trial. Ophthalmology. 2008;115(11):1876-82.
  41. Lee SH, Jeong E, Paik SS, et al. Cyanidin-3-glucoside extracted from mulberry fruit can reduce N-methyl-N-nitrosourea-induced retinal degeneration in rats. Curr Eye Res. 2014 Jan;39(1):79-87.
  42. Tremblay F, Waterhouse J, Nason J, et al. Prophylactic neuroprotection by blueberry-enriched diet in a rat model of light-induced retinopathy. J Nutr Biochem. 2013 Apr;24(4):647-55.
  43. Matsumoto H, Nakamura Y, Tachibanaki S, et al. Stimulatory effect of cyanidin 3-glycosides on the regeneration of rhodopsin. J Agric Food Chem. 2003 Jun 04;51(12):3560-3.
  44. Tirupula KC, Balem F, Yanamala N, et al. pH-dependent interaction of rhodopsin with cyanidin-3-glucoside. 2. Functional aspects. Photochem Photobiol. 2009 Mar-Apr;85(2):463-70.
  45. Yanamala N, Tirupula KC, Balem F, et al. pH-dependent interaction of rhodopsin with cyanidin-3-glucoside. 1. Structural aspects. Photochem Photobiol. 2009 Mar-Apr;85(2):454-62.
  46. Available at: Accessed June 24, 2019.
  47. Nakaishi H, Matsumoto H, Tominaga S, et al. Effects of black current anthocyanoside intake on dark adaptation and VDT work-induced transient refractive alteration in healthy humans. Altern Med Rev. 2000 Dec;5(6):553-62.