Cataracts are a common age-related eye condition that cause the lens of the eye to become cloudy, leading to blurred vision, glare sensitivity, and, in severe cases, vision loss. While cataracts typically develop in older adults, some people experience them much earlier in life. The question is: why do cataracts affect some individuals sooner than others?
A combination of genetic, environmental, and lifestyle factors plays a role in determining when cataracts develop. Understanding these factors can help individuals take proactive steps to protect their vision for as long as possible.
1. Genetic Predisposition
Genetics plays a significant role in determining when and how cataracts develop, as hereditary factors influence the overall structure and resilience of the eye’s lens. If a close family member—such as a parent, grandparent, or sibling—experienced cataracts at a young age, there is an increased likelihood that future generations may inherit the same predisposition. This is because certain genetic traits related to lens composition, protein stability, and cellular repair mechanisms are passed down through families, making some individuals more vulnerable to early cataract formation.
One of the primary ways genetics contributes to early-onset cataracts is through inherited disorders. Congenital cataracts, for example, are present at birth or develop in early childhood due to mutations in genes responsible for lens transparency. Conditions such as Down syndrome, Marfan syndrome, and galactosaemia are also associated with a higher risk of cataract development at an unusually young age.
Beyond congenital cases, genetic mutations can impact how the lens responds to oxidative stress and environmental damage over time. The human eye is constantly exposed to factors that contribute to cellular ageing, such as UV radiation, metabolic by-products, and inflammation. Some people have a naturally stronger ability to counteract this damage due to protective enzymes and antioxidants encoded in their genes. However, those with genetic variations that impair these defence mechanisms may experience earlier and more severe lens clouding.
Additionally, research suggests that certain gene variants involved in lens protein maintenance and hydration regulation may accelerate cataract formation. The lens is made up of proteins called crystallins, which help maintain its clarity and function. If genetic mutations affect how these proteins are produced, folded, or repaired, the lens may become clouded earlier than expected.
While genetic predisposition is not something that can be altered, individuals with a family history of early cataracts can take preventive measures, such as protecting their eyes from UV exposure, maintaining a healthy diet rich in antioxidants, and scheduling regular eye exams to detect any early signs of lens changes. Understanding the genetic influence on cataract development can help individuals make informed decisions about their eye health and take proactive steps to delay the onset of vision impairment.
2. Exposure to UV Light
Exposure to ultraviolet (UV) light is a major environmental factor in the early development of cataracts. The sun emits three types of UV radiation: UVA, UVB, and UVC. While UVC is mostly absorbed by the Earth’s atmosphere, UVA and UVB rays penetrate the eyes and can cause long-term damage to the lens. Over time, repeated exposure to UV radiation leads to oxidative stress in the lens, damaging its proteins and reducing its transparency. This gradual clouding is what ultimately results in cataracts.
The lens of the eye is designed to filter out some UV radiation, but it does not provide complete protection. When exposed to excessive sunlight without proper eye protection, the lens absorbs more UV rays than it can handle, accelerating the breakdown of essential proteins and fibres that maintain its clarity. This process can begin years before any noticeable vision problems occur, making early prevention crucial.
Certain groups are at a higher risk of UV-induced cataracts due to their lifestyle or occupation. Individuals who spend long hours outdoors, such as farmers, fishermen, construction workers, and athletes, are particularly susceptible. The risk is even greater in regions with high sun exposure, such as tropical and desert climates, or in environments with reflective surfaces like snow, water, or sand, which intensify UV radiation exposure.
Even those who do not work outdoors can be at risk if they frequently engage in outdoor activities such as hiking, running, skiing, or driving for extended periods without adequate eye protection. Additionally, people who live at higher altitudes are exposed to stronger UV radiation, as the thinner atmosphere filters out fewer rays.
To reduce the risk of early cataract development due to UV exposure, wearing high-quality sunglasses with UV-blocking lenses is essential. Not all sunglasses offer sufficient protection, so it is important to choose ones that block 100% of UVA and UVB rays. Wraparound sunglasses provide additional shielding by preventing UV rays from entering from the sides. Wearing a wide-brimmed hat can also help reduce direct sunlight exposure to the eyes.
Moreover, UV exposure is not limited to sunny days—cloudy or overcast conditions still allow a significant amount of UV radiation to reach the eyes. This means that eye protection should be worn year-round, regardless of the weather. People who frequently use tanning beds or work with artificial UV sources, such as welders and laboratory technicians, should also take extra precautions, as these environments can expose the eyes to intense UV radiation.
By being mindful of UV exposure and taking proactive steps to protect the eyes, individuals can significantly reduce their risk of developing cataracts at an early age and maintain clearer vision for longer.
3. Medical Conditions
Several medical conditions can accelerate cataract formation, causing some individuals to develop them much earlier than expected. These conditions often contribute to metabolic imbalances, chronic inflammation, or increased oxidative stress, all of which can weaken the eye’s lens and speed up the clouding process. Understanding these risk factors can help individuals take preventative measures to protect their vision.
Diabetes
Diabetes is one of the most well-documented risk factors for early cataract development. High blood sugar levels affect the lens in multiple ways, leading to premature clouding. Excess glucose in the bloodstream can enter the eye’s lens, where it is converted into sorbitol. This sugar alcohol accumulates in the lens, disrupting its normal structure, drawing in excess water, and leading to swelling and distortion. Over time, this process affects lens transparency, resulting in cataract formation.
Diabetic individuals are at a significantly higher risk of developing cataracts at a younger age, especially if their blood sugar levels are poorly controlled. Additionally, diabetes-related complications such as diabetic retinopathy and oxidative stress further increase vulnerability to vision problems. The longer a person has diabetes, the greater their risk, making regular eye check-ups essential for early detection.
Hypertension (High Blood Pressure)
Uncontrolled hypertension can negatively impact eye health in several ways. Chronic high blood pressure damages blood vessels throughout the body, including those that supply oxygen and nutrients to the eyes. Reduced blood flow can lead to oxidative stress in the lens, increasing the likelihood of early cataract formation.
Additionally, hypertension is often associated with other metabolic disorders, such as diabetes and high cholesterol, which collectively heighten the risk of cataracts. Medications used to manage hypertension, such as beta-blockers and diuretics, may also play a role in lens changes, although their direct impact on cataract formation is still being studied.
Obesity
Excess weight is linked to several metabolic and inflammatory processes that can contribute to early cataract development. Obesity often leads to insulin resistance, which can increase the risk of type 2 diabetes—another major cataract risk factor. Additionally, chronic low-grade inflammation associated with obesity generates oxidative stress, which accelerates the ageing of the eye’s lens.
Obese individuals may also have lower levels of antioxidants in their diet, which are essential for protecting the eyes from damage. A diet high in processed foods, refined sugars, and unhealthy fats can deprive the body of nutrients like vitamin C, vitamin E, and lutein—compounds that help maintain lens health and prevent early cataract formation.
Autoimmune Diseases
Autoimmune conditions, such as rheumatoid arthritis, lupus, and multiple sclerosis, are known to contribute to early cataracts. These diseases involve chronic inflammation and immune system dysfunction, which can indirectly affect eye health. Inflammation in the body can accelerate oxidative stress and damage the delicate proteins in the eye’s lens, leading to premature clouding.
A significant risk factor in autoimmune-related cataract formation is the long-term use of corticosteroids. These medications, commonly prescribed to control inflammation and suppress the immune system, have a well-established link to early cataract development. Steroid-induced cataracts typically form in the posterior subcapsular region of the lens, which can cause rapid vision deterioration.
Other autoimmune-related complications, such as Sjögren’s syndrome, which affects tear production and leads to chronic dry eyes, can exacerbate overall eye health issues and make cataract symptoms more pronounced.
Other Medical Conditions That May Influence Cataract Development
In addition to the major conditions mentioned above, several other health issues may contribute to early cataract formation:
- Chronic kidney disease (CKD): Patients with kidney disease often have imbalances in calcium and phosphate levels, which can lead to metabolic changes that impact the lens.
- Thyroid disorders: Both hyperthyroidism and hypothyroidism have been associated with an increased risk of cataracts due to their effects on metabolism and oxidative stress.
- Neurological conditions: Some studies suggest that neurodegenerative diseases like Alzheimer’s may have a link to early cataract development, possibly due to shared mechanisms of protein misfolding in the brain and lens.
Managing and Reducing Risk
While many of these conditions cannot be entirely prevented, managing them effectively can help reduce the risk of early cataract formation. This includes:
- Maintaining good blood sugar control in diabetic individuals through diet, medication, and regular monitoring.
- Managing blood pressure and cholesterol levels to reduce oxidative stress on the eyes.
- Adopting a healthy diet rich in antioxidants, vitamins, and omega-3 fatty acids to support eye health.
- Avoiding long-term steroid use unless absolutely necessary, and exploring alternative treatments for autoimmune conditions.
- Engaging in regular physical activity to improve overall metabolic health and reduce inflammation.
- Scheduling routine eye exams to detect early signs of cataract formation and other vision-related complications.
By being proactive about managing underlying health conditions, individuals can significantly delay cataract development and maintain clearer vision for longer.
4. Smoking and Alcohol Consumption
Smoking is one of the most well-established risk factors for early cataract development. The toxins in cigarette smoke increase oxidative stress in the eye, leading to lens damage. Heavy smokers are several times more likely to develop cataracts earlier than non-smokers.
Excessive alcohol consumption can also contribute to cataract formation. Chronic alcohol intake may deplete the body of essential antioxidants, increasing the risk of oxidative damage in the lens.
5. Use of Certain Medications
Some medications can speed up cataract development, particularly:
- Corticosteroids – Long-term use of steroid medications (for asthma, autoimmune diseases, or chronic inflammatory conditions) is a well-known cause of early cataracts.
- Chlorpromazine and Other Antipsychotics – Some psychiatric medications can contribute to cataract formation when used over long periods.
- Statins – Although statins are widely used to lower cholesterol, some studies suggest a possible link between long-term statin use and an increased risk of cataracts.
6. Eye Injuries and Trauma
Physical injury to the eye, such as blunt force trauma, penetrating injuries, or exposure to radiation, can damage the lens and lead to early cataract development. This type of cataract, known as traumatic cataract, can occur even in younger individuals following an injury.
People involved in high-risk activities, such as contact sports or professions that expose them to potential eye trauma, should always use protective eyewear.
7. Poor Nutrition and Deficiency in Antioxidants
A diet lacking in essential vitamins and antioxidants can contribute to early cataract formation. The eye’s lens relies on nutrients such as:
- Vitamin C – Helps protect against oxidative damage.
- Vitamin E – Supports eye health by reducing inflammation.
- Lutein and Zeaxanthin – Found in leafy greens, these carotenoids help filter harmful blue light and protect the lens.
- Omega-3 Fatty Acids – Found in fish and flaxseeds, they support overall eye health.
People with diets high in processed foods, refined sugars, and unhealthy fats may experience cataract development earlier than those with nutrient-rich diets.
8. Chronic Dehydration
Hydration plays a crucial role in maintaining the clarity of the lens. Chronic dehydration can contribute to protein clumping in the lens, which leads to cataract formation. People who do not drink enough water regularly may have a higher risk of developing cataracts earlier than those who stay well-hydrated.
9. Exposure to Blue Light and Digital Screens
While research is ongoing, some evidence suggests that excessive exposure to blue light from digital devices may contribute to oxidative stress in the eyes. Although blue light is not a direct cause of cataracts, prolonged screen time without protective measures (such as blue light filtering glasses) may increase overall eye strain and damage over time.
10. Radiation Exposure
People exposed to radiation—whether through cancer treatments, occupational hazards, or excessive X-rays—are at an increased risk of developing cataracts earlier. Radiation can damage the lens cells, accelerating the clouding process.
Can Early Cataracts Be Prevented?
While some risk factors, such as genetics, cannot be changed, several lifestyle adjustments can help delay cataract onset:
- Wear UV-blocking sunglasses to protect the eyes from sun damage.
- Maintain a healthy diet rich in antioxidants, vitamins, and omega-3 fatty acids.
- Stay hydrated to keep the lens clear and healthy.
- Avoid smoking and limit alcohol intake to reduce oxidative stress.
- Manage chronic health conditions like diabetes and high blood pressure.
- Reduce prolonged screen exposure and use blue light filters when necessary.
- Use protective eyewear if engaged in high-risk activities or occupations.
Final Thoughts
Cataracts can develop earlier in some people due to a combination of genetic, environmental, and lifestyle factors. Understanding these risk factors can help individuals take proactive steps to protect their vision for as long as possible. Regular eye check-ups are essential for detecting early cataract changes, allowing for timely intervention and management. By adopting healthier habits and minimising exposure to known risk factors, many people can delay cataract formation and maintain clearer vision for longer.