Few consequences of aging threaten independence as profoundly as vision loss and blindness.

Progressive deterioration of the retina, optic nerve, or lens can take away the ability to read, drive, recognize faces, and navigate the world independently.

Age-related eye diseases such as cataracts, glaucoma, and macular degeneration are remarkably common.Cataracts impact many older adults but are surgically reversible.¹

Glaucoma, on the other hand, is a leading cause of irreversible blindness.² Macular degeneration is also a leading cause of irreversible central blindness, though it often spares peripheral (side) vision and does not obliterate all light perception.³

Some evidence suggests that lifestyle and dietary measures may reduce the risk or slow the progression of certain degenerative eye diseases, though high-quality proof of prevention is limited and varies by condition.³

When it comes to glaucoma or optic nerve degeneration, caused by higher than tolerable intraocular pressure, certain methods can reduce this pressure to low normal ranges and thus can protect against further nerve damage/visual loss.

The challenge today is that many people remain fixated on keeping intraocular pressure below 22 mmHg

Overlooked is that high "normal" eye pressure levels may be causing optic nerve damage in at-risk individuals. In these cases, established interventions can reduce intraocular pressure to lower "normal" levels and thus protect against this type of optic nerve deterioration.

Prevention of degenerative eye diseases deserves far more attention than it typically receives.⁴ This editorial describes practical methods to help protect our aging eyes.

Major Eye Pressure Study in 1998

The Collaborative Normal-Tension Glaucoma Study, published in 1998, was probably the most important turning point for the concept of lowering eye pressure (intraocular pressure [IOP]) in patients at risk of glaucoma progression, even when pressure is already within the conventional normal range.⁹

The study enrolled people with normal-tension glaucoma, a form of glaucoma that occurs despite eye pressure that was traditionally considered normal at the time. Eligible eyes were randomized to either observation (no treatment) or a 30% reduction from baseline in eye pressure using eye drops, laser treatment, or filtering surgery (trabeculectomy).

The results suggested that lowering eye pressure can slow the progression of glaucoma in these at-risk patients.

Major Types of Age-Related Vision Loss

In macular degeneration, damage accumulates in and around the macula, the small central region of the retina responsible for our high-resolution, color, and central vision.^5,6

In cataracts, proteins in the lens become damaged and aggregate, reducing transparency.⁷

In glaucoma, optic nerve fibers progressively die, often in association with elevated intraocular pressure.⁸

The benefit became clear only after accounting for the confounding effects of treatment-related cataracts (some glaucoma surgeries like the trabeculectomy can increase the risk of cataracts).

In this study, if someone's untreated eye pressure was:

• 18: then the target was around 12.6
• 17: 11.9
• 16: 11.2
• 15: 10.5 mmHg

These values are provided solely as arithmetic examples of 30% reduction and should not be interpreted as individualized treatment targets. Target eye pressure (IOP) is determined on a patient-by-patient basis according to disease severity, baseline pressure, risk factors, and rate of progression.

Following this trial, additional randomized clinical trial evidence found that intentionally lowering/targeting eye pressure well below the traditional "normal" threshold in selected patients resulted in slowed progression of glaucoma.^10,11

A Second Study Reinforced This Idea in 2000

The Advanced Glaucoma Intervention Study published an influential analysis in 2000 showing a strong relationship between sustained eye pressure (IOP) control and visual-field preservation in patients with advanced glaucoma.¹²

A particularly influential observation was that patients whose pressures remained below 18 mmHg at every study visit had an average eye pressure of approximately 12.3 mmHg and, as a group, showed essentially no average deterioration in visual-field score over years of follow-up.

That helped popularize the idea that 12–14 mmHg could be an entirely appropriate therapeutic pressure, especially in advanced glaucoma.

It's important to note that the study only found a link between the outcome and lower intraocular pressure; it did not directly test 12 mmHg against 17 mmHg. Therefore, the results do not show that everyone should target 12 mmHg.

Current Eye Pressure Guidelines

Current guidelines for early-stage glaucoma or early optic nerve damage in primary open-angle glaucoma generally recommend lowering intraocular pressure by 20% to 30% below baseline levels. If the baseline intraocular pressure was 18 mmHg, the target would be to reduce it to around 14.4 to 12.6 mmHg (or lower) to protect against further optic nerve damage.¹³ Treatment goals should be individualized based on factors such as age, risk profile, and the extent of optic nerve damage.¹⁴

Eye pressure can be lowered by prescription eye drops, laser surgery, or incisional surgery (alone or in combination). Each carries its own risks and benefits. The best course of action is decided by the physician and patient together based on individual needs.

Refer to the box on this page for treatment target examples.

Macular Degeneration

Macular degeneration is progressive damage to the central retina that reduces high-resolution central vision, most commonly as a consequence of aging.⁵

Pooled results from clinical trials have found that higher intakes of the carotenoids lutein, zeaxanthin, and meso-zeaxanthin can increase macular pigment optical density.¹⁶ This would be expected to reduce the risk of macular degeneration.

Some studies involving these carotenoids have also reported improvements in different eye measures such as distinguishing objects from their background (contrast sensitivity), seeing comfortably in bright light (glare tolerance), and recovering more quickly after exposure to a bright light (photostress recovery).^17,18

Cataracts

Certain nutrients may reduce the risk of cataracts.

From a preclinical standpoint, carnosine may help protect against protein crosslinking caused by glycation, a process in which sugar reacts with protein and which is thought to contribute significantly to cataract formation.¹⁹ As humans age, glycation reactions occur more frequently throughout the body and contribute to age-related tissue damage. This damage plays a role in advanced age-associated pathologies of the circulatory system, the eyes, the nervous system, and vital organs.²⁰

Short-wavelength blue light contains more energy per photon than longer-wavelength visible light, and laboratory studies show that sufficiently intense blue light can generate oxidative damage in retinal cells.²³

However, this does not mean that blue light from ordinary smartphones and computer monitors is destroying the retina.

Current evidence has not clearly demonstrated that typical screen exposure causes retinal degeneration in humans. The blue light emitted by screens is also vastly less intense than sunlight.²⁴

Internal Protective Nutrients

Among the most intriguing nutritional factors involved in ocular health are three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin.¹⁶

These pigments are unusual because the eye actively concentrates them in the macula, where they form what is known as macular pigment.¹⁶

Their location is important. Macular pigment sits directly in front of some of the retina's most metabolically active and visually important cells.

Lutein and zeaxanthin appear to benefit the eye in two principal ways.

First, they function as antioxidants, helping neutralize reactive oxygen species generated by metabolism and light exposure.¹⁶

Second, they absorb short-wavelength visible light, particularly portions of the blue spectrum, before that light reaches the underlying photoreceptors and retinal pigment epithelium.²¹

In effect, the retina constructs its own internal light filter using carotenoids obtained from the diet.²²

Sunlight remains the more significant environmental light exposure, particularly because ultraviolet (UVB) radiation can contribute to a form of cataracts,²⁵ which supports the value of routine UV-blocking eye protection.

The sensible position is therefore between two extremes. Blue light is not inherently harmless to the eyes, but neither is every digital screen a retinal hazard.

Preserving Vision Before It Is Lost

The strongest preventive measures to reduce the risk of eye diseases remain straightforward: do not smoke, control blood pressure and diabetes, exercise, eat a nutrient-rich diet, and protect the eyes from excessive ultraviolet exposure.^26,27

Foods rich in lutein and zeaxanthin include spinach, kale, collard greens, eggs, corn, and other yellow and green vegetables.²²

We devote enormous attention to preserving the heart, brain, muscles, and skin as we age. The retina deserves the same consideration.

For longer life,

William Faloon, Co-Founder, Life Extension®

References

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2. Stein JD, Khawaja AP, Weizer JS. Glaucoma in Adults-Screening, Diagnosis, and Management: A Review. JAMA. 2021 Jan 12;325(2):164-74.
3. Fleckenstein M, Schmitz-Valckenberg S, Chakravarthy U. Age-Related Macular Degeneration: A Review. JAMA. 2024 Jan 9;331(2):147-57.
4. Scott AW, Bressler NM, Ffolkes S, et al. Public Attitudes About Eye and Vision Health. JAMA Ophthalmol. 2016 Oct 1;134(10):1111-8.
5. Available at: https://www.aao.org/eye-health/diseases/amd-macular-degeneration. Accessed 08/11/2026.
6. Koksaldi S, Kayabasi M, Karti O, et al. Clinical anatomy of the macula. Med Hypothesis Discov Innov Ophthalmol. 2025 Summer;14(2):17-27.
7. Available at: https://www.aao.org/eye-health/diseases/what-are-cataracts. Accessed 08/11/2026.
8. Available at: https://www.aao.org/eye-health/diseases/what-is-glaucoma. Accessed August 11, 2026.
9. Group CN-TGS. Comparison of glaucomatous progression between untreated patients with normal-tension glaucoma and patients with therapeutically reduced intraocular pressures. Collaborative Normal-Tension Glaucoma Study Group. Am J Ophthalmol. 1998 Oct;126(4):487-97.
10. Heijl A, Leske MC, Bengtsson B, et al. Reduction of intraocular pressure and glaucoma progression: results from the Early Manifest Glaucoma Trial. Arch Ophthalmol. 2002 Oct;120(10):1268-79.
11. Araujo-Azevedo B, Ferreira-da-Silva R, Barbosa-Breda J. The efficacy and safety of reducing intraocular pressure to single-digit levels in Normal-tension glaucoma: A systematic review and meta-analysis. Acta Ophthalmol. 2026 Mar 20.
12. AGIS. The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration.The AGIS Investigators. Am J Ophthalmol. 2000 Oct;130(4):429-40.
13. Gedde SJ, Bowden EC, Challa P, et al. Primary Open-Angle Glaucoma Preferred Practice Pattern(R). Ophthalmology. 2026 Apr;133(4):P1-P103.
14. Available at: https://www.guidelinecentral.com/guideline/309953/#section-5100388. Accessed August 11, 2026.
15. Polski A, Brintz BJ, Hess R, et al. Influence of Intraocular Pressure on Clinical Decision-Making in Glaucoma Management. JAMA Ophthalmol. 2026 Feb 1;144(2):167-73.
16. Wilson LM, Tharmarajah S, Jia Y, et al. The Effect of Lutein/Zeaxanthin Intake on Human Macular Pigment Optical Density: A Systematic Review and Meta-Analysis. Adv Nutr. 2021 Dec 1;12(6):2244-54.
17. Stringham JM, O'Brien KJ, Stringham NT. Contrast Sensitivity and Lateral Inhibition Are Enhanced With Macular Carotenoid Supplementation. Invest Ophthalmol