What Are Cataracts (And How Can You Avoid Them)?

Getting your Trinity Audio player ready...

It’s Summer, the Sun is shining and the days are long. Most people know about the dangers of UV light and the importance of sunscreen when it comes to photoageing and skin cancer. Yet your skin isn’t the only tissue that needs protection from the Sun’s rays – you need to think about the lenses in your eyes too! Cataracts are a common eye condition that affects millions of people worldwide. They primarily occur in older individuals and can significantly impact vision. In this article, we will explore what cataracts are, their causes, and how you can best prevent them.

What are Cataracts?

Cataracts are a clouding of the lens in the eye, leading to a progressive loss of vision. The lens is a transparent structure located behind the iris, responsible for focusing light onto the retina. It’s an unusual tissue – it contains long cells that receive no blood supply, instead obtaining nutrients from the surrounding fluid within the eye. The lens also contains a higher concentration of proteins than any other tissue, and it’s the special properties of these proteins that allow the lens to be transparent and flexible. 

These two properties are essential for the lens to function correctly. In cataracts, the proteins of the lens start to clump together, forming tiny crystals that scatter light and make the lens cloudy and opaque. Cloudy lenses can be surgically removed and replaced with an artificial lens if they are interfering with daily life, but this is not without risk, so it’s better if cataracts can be avoided entirely.

What Causes Cataracts?

Cataract formation is a gradual process and there are multiple contributing factors:

• Prolonged exposure to ultraviolet (UV) radiation from sunlight and other sources. UV radiation damages the lens and the skin in similar ways. In the lens, UV light damages proteins through glycation, a process in which sugar molecules bind to proteins and link them together.
• Certain medical conditions such as diabetes and hypertension. Elevated blood sugar in diabetes can lead to damage to the lens through glycation and oxidative stress. Hypertension can damage blood supply to the eye, leading to oxidative stress in the lens.
• Eye injuries or trauma.
• Long-term use of corticosteroid medications. The mechanisms for this aren’t well understood.
• Smoking. Smoking can damage the lens by promoting oxidative stress throughout the body.

Why are Cataracts More Common in Older Age Groups?

95% of cataracts are in people over the age of 50. Cataract development is a slow, cumulative process, so older people are more likely to have cataracts simply because their lenses have been exposed to more UV light throughout life. However, there are also some age-related changes that make older people more at risk of cataracts.

We already mentioned blood sugar in diabetes and blood pressure as risk factors for cataracts, and both of these metrics tend to increase in older age. Ageing tissues are also less resistant to oxidative stress, which is a source of damage to the lens proteins. Cells within the lens are capable of repairing or recycling damaged proteins, but their ability to do this declines with age. All this means that older people tend to accumulate lens damage more rapidly than younger people, though cataracts can still occur in younger age groups.

Preventing Cataracts:

While it may not be possible to completely prevent cataracts, certain measures can help reduce the risk of developing them or delay their onset. Here are some preventive steps:

• Protect your eyes from UV radiation: Wear sunglasses that block both UVA and UVB rays when you are outdoors. Remember that clouds only block some UV light, so the danger posed by UV radiation doesn’t necessarily correspond to the perceived brightness of the Sun. Also remember that while the Sun may not be as strong in winter, you are more likely to be looking directly towards it because it spends more time close to the horizon.
• Maintain a healthy lifestyle: Eat a balanced diet rich in fruits, vegetables, and antioxidants. Exercise regularly and maintain a healthy weight.
• Quit smoking: Smoking has been linked to an increased risk of cataract formation. Quitting smoking can have numerous health benefits, including reducing the risk of cataracts.
• Manage underlying health conditions: Control conditions such as diabetes and hypertension through proper medical care, as these conditions can increase the risk of cataracts.
• Regular eye exams: Schedule regular comprehensive eye exams to monitor your eye health and detect any early signs of cataracts.

---

Like ageing itself, you cannot fully prevent the progression of cataracts, but you can slow it down significantly. Following the above advice will also reduce the risk of other eye conditions like glaucoma and macular degeneration.