Can Exercise Delay Cataracts? What the Research Suggests
Please hit the ❤️ at the top or bottom of this email to help others discover All About Vision With Dr. Kondrot. Your subscription directly supports my ongoing humanitarian work—delivering free eye surgeries and care where it's needed most.
Story at a Glance
Cataracts—clouding of the lens—are often seen as inevitable with aging. But growing evidence suggests regular physical activity may slow their onset or progression. Exercise may act by reducing oxidative stress, improving circulation, regulating metabolism, and tamping inflammation.
1. How Cataracts Develop — and Why Exercise Might Help
Lens Biochemistry & Damage
Your lens is transparent largely because its protein structure (crystallins) remains highly ordered and stable. Over decades, cumulative damage—especially from oxidative stress—can denature proteins, cause aggregation, and scatter light, producing cloudiness. Aging, UV exposure, smoking, diabetes, and metabolic stress accelerate these changes.
Because the lens lacks blood vessels and turnover, damage is cumulative. Repair is limited.
Mechanisms by Which Exercise May Help
Exercise has systemic effects that can, in principle, protect the lens:
Boost antioxidant defenses: Exercise induces endogenous antioxidant enzymes (e.g. superoxide dismutase, glutathione peroxidase) which may help buffer reactive oxygen species impacting lens proteins.
Reduce inflammation: Physical activity is known to lower systemic inflammatory mediators (e.g. C-reactive protein), which may otherwise contribute to lens oxidative injury.
Improve metabolic health: Exercise helps control blood sugar, lipids, and insulin resistance—key risk modifiers for cataract development, especially in diabetic patients.
Enhance microcirculation: Better vascular health supports surrounding ocular tissues (though not direct lens blood flow) and may reduce oxidative load near the lens.
Dose-response relation: Meta-analysis of prospective studies suggests for every 6 METs/day increase in activity, cataract risk declines ~2%.
Thus, exercise doesn’t directly “clean” the lens, but it enhances the systemic environment so the lens is under less stress.
2. What the Clinical Evidence Shows
The idea that exercise may delay or reduce cataract formation is supported by observational and genetic studies—but with caveats.
Meta-Analysis & Prospective Cohorts
A meta-analysis of six prospective studies (171,620 participants, 19,173 cataract cases) showed that higher physical activity was associated with a ~10% reduction in age-related cataract risk (RR = 0.90).
The dose-response analysis within that meta-study estimated a 2% risk reduction per 6 METs of daily activity.
In a large Swedish cohort (52,660 adults over ~12 years), those in the highest quartile of total physical activity had a 13% lower hazard of cataract relative to the lowest quartile (HR ~0.87).
In another long-term study, both walking and running showed similar cataract risk reduction per MET-hour per day.
Mendelian Randomization (Genetic) Evidence
A recent Mendelian randomization (MR) study suggests a causal protective effect: genetically predicted moderate or vigorous physical activity ≥10 min/week was associated with lower risk of senile cataract (OR ~0.76 for moderate, ~0.69 for vigorous).
These MR findings strengthen the possibility that the association is not wholly due to healthy-person bias (i.e. active people being healthier in other ways).
Limitations & Gaps
Observational studies are subject to confounding (e.g. those who exercise more may smoke less, eat better, have better access to care).
Exercise types are variably defined; self-reported activity is subject to recall bias.
There is less strong data on progression of existing cataract vs prevention of onset.
Many studies do not stratify cataract subtypes (nuclear, cortical, posterior subcapsular), which may differ in how much they respond to systemic factors.
In sum, the body of evidence is promising, but not definitive—yet enough to view exercise as a potentially beneficial, low-risk tool in your eye health program.
3. Conventional Strategies to Protect Your Lens
Before relying on exercise, these evidence-based strategies remain foundational:
a. UV Protection
Wearing UV-blocking sunglasses and brimmed hats reduces photic stress to lens fibers.
b. Smoking Cessation
Tobacco increases oxidative load; quitting is among the strongest modifiable protections.
c. Management of Systemic Risk Factors
Diabetes control (especially for patients with or at risk of cataract)
Hypertension and vascular health
Lipid control and protection against dyslipidemia
d. Nutritional Antioxidant Supplementation (as indicated)
In some settings, supplementation (e.g. vitamin C, E, carotenoids) is used to support ocular antioxidant reserves—though the evidence for cataract prevention is less strong than for other eye diseases.
e. Early Surgical Intervention
When cataract becomes visually significant, timely cataract surgery is the definitive therapy—preceded by planning to optimize outcomes (pre-op health, controlling comorbidities, ensuring intraocular lens choice).
These pillars are the backbone; exercise is a supportive adjunct.
4. Holistic & Natural Supports to Amplify Benefit
To strengthen your lens resilience beyond traditional care, consider integrating the following:
a. Anti-oxidant Nutrition & Micronutrients
A diet rich in leafy greens, colorful fruits and vegetables, nuts, seeds, and carotenoid sources supports systemic antioxidant capacity.
Specific nutrients (e.g. lutein, zeaxanthin, vitamin C, vitamin E) may help reduce ocular oxidative stress (though direct cataract-delay evidence is limited).
Ensure trace minerals (zinc, selenium) which participate in antioxidant enzyme systems.
b. Maintenance of Glycemic & Metabolic Health
A low glycemic load diet, avoiding chronic glucose spikes
Healthy fats (omega-3s) rather than saturated or trans fats
Weight control, insulin sensitivity support (exercise, sleep, stress management)
c. Lifestyle & Stress Regulation
Adequate sleep and circadian alignment
Stress reduction (meditation, breathing, yoga) to reduce cortisol and oxidative burden
Avoiding environmental toxins (smoking, pollution, heavy metals) that may exacerbate lens damage
d. Microcirculatory & Mitochondrial Support
Some integrative practitioners trial photobiomodulation (low-level red or near-infrared light) to support mitochondrial function—experimental and to be used cautiously
Nutraceuticals targeting mitochondrial health (e.g. Coenzyme Q10, PQQ, NAC) may indirectly assist—but must be coordinated with your eye care provider
e. Moderate Exercise Prescription
Moderate-to-vigorous exercise (30+ min sessions most days) is ideal; both walking and more intense activity have shown benefit.
Incremental increases are better than all-or-nothing
Choose low-impact modalities if joints or mobility are a concern (swimming, cycling, brisk walking)
These holistic supports don’t guarantee protection, but they align conditions to favor slower cataract progression.
5. Build Your Lens-Friendly Exercise Plan & Monitoring Strategy
Here’s how to safely make exercise a consistent part of your eye health toolkit:
a. Start Sensibly
Begin with moderate intensity: brisk walking, cycling, swimming
Aim for at least 150 minutes per week of moderate or 75 minutes of vigorous (or combination) per standard guidelines
Use the progressive overload principle: increase gradually (time, frequency, intensity)
b. Diversify and Protect
Mix in strength training (2–3x/week) to support systemic health
Include flexibility, balance, and movement variety
Always wear UV protection outdoors
Hydrate well; avoid excessive heat, glare, or dehydration stress on tissues