Cataracts, for the most part, is a result of the normal ageing process of the eyes. The once clear crystalline that focuses light to your macular starts becoming more clouded and yellowish over time. There are different forms of cataracts such as nuclear sclerosis, subcapsular cataracts and cortical cataract. Though they differ in certain ways, all of them result in a deterioration of vision over time.
Besides ageing, cataracts can be due to exposure to UV radiation over time, congenital (i.e. from birth), diabetes, certain drugs and medications. All of which results in the clouding of the crystalline lens. Typically, signs of cataracts occur in those over 65 years old but the extent can vary among individuals. It can develop earlier depending on certain risk factors. The rate of change in vision due to cataracts varies on every individual and even between the two eyes. I’ve seen some cataracts go from just traces to very cloudy and needing to be removed in a matter of months. And on the other end of the scale, I’ve seen patients who have had cataracts for 10-20 years without it affecting their vision to a degree that needed surgery.
Typically, early signs may not be noticed at all, but your optometrist may detect early changes to the crystalline lens such as a slight change in colour or clouded area in the lens where it may not be causing an effect to vision quality. However, with time, the typical symptoms are blurred vision, sensitivity to glare and distortion of vision. You may also have a reduction in clarity when trying to do fine tasks, especially at night due to a reduction in contrast.
Although there is no way to prevent the normal ageing process of the eye, good UV protection, a healthy diet and no smoking can certainly help reduce your risk factors.
Treatment usually starts with corrective glasses, as the density of the cataract changes – so does the refractive properties of the lens which focuses the light to the macular. Hence, your spectacle prescription is adjusted accordingly – remembering cataracts can change rapidly over a few months or slowly over years. We do this until a certain point, where a limit is reached in your visual acuity and the cataract is bad enough to be removed. Otherwise, early intervention is required if the cataracts affect your day-to-day life due to glare sensitivity or fogginess.
When surgery is required, it is a minor operation under local anaesthetic. You get to go home the same day. Surgery is performed by an Ophthalmologist who removes the clouded lens to replaced it with an Intra-ocular lens (IOL). Once replaced with the artificial lens, the cataract can’t return, and most people have relatively excellent vision afterwards.