Cataracts are cloudy areas that form in the lens, a transparent structure that lets light into the eye. A cataract causes part of the lens to become opaque. Light does not pass through easily, and vision becomes blurry, like looking through a fogged-up window. The cloudier the lens, the worse vision will be.
Cataracts are the leading cause of vision loss in people over the age of 40, but cataract surgery is now a routine operation and the most common kind of eye surgery. Today, cataract surgery is a safe and effective procedure, resulting in a dramatic improvement in quality of life.
For most people, cataracts are a natural result of aging, but people with diabetes tend to get cataracts more commonly and at a younger age.
How do cataracts affect vision?
Cataracts can make it hard to read or drive a car, especially at night. Seeing people’s facial expressions can become difficult.
They develop slowly, so most people do not know they have them at first, but as clouding progresses, vision gradually gets worse. Long-distance vision is more severely affected at the beginning.
As vision deteriorates, and the glare of oncoming headlights and streetlights worsens, driving becomes dangerous. Drivers with cataracts start to experience eyestrain and find themselves blinking more frequently as they try to clear their vision.
Stronger lighting and glasses can help improve vision, but eventually it becomes harder to carry out everyday tasks, by which stage, surgery is necessary.
Cataracts normally take years to develop, and tend to appear in older age when the lens gradually becomes cloudy. Cataracts often affect both eyes, but rarely equally.
People with cataracts may experience the following symptoms:
- Blurry, cloudy, or misty vision
- Vision may be affected by small spots or dots
- The patient sees small patches that blur parts of the field of vision
- Vision worsens when lights are dim – or in very bright light
- Colours appear less clear and faded
- Reading becomes difficult and eventually impossible
- Eventually wearing glasses becomes less effective
- Rarely, the person may see a halo around bright objects, such as car headlights or streetlights, or have double vision in one eye