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