A cataract is a clouding of the natural lens inside the eye — the transparent structure responsible for focusing light onto the retina to produce clear, sharp images. As the lens becomes progressively opaque, vision gradually dims, colours appear washed out, sensitivity to bright lights and glare increases, and reading becomes more difficult. Cataracts are among the most common causes of reversible vision impairment globally, and they are particularly prevalent in adults over the age of 50, though they can develop at any age due to injury, medication, or systemic conditions such as diabetes.

Unlike a basic vision check that only determines whether you need glasses, a complete eye examination includes an evaluation of eye pressure, the condition of the lens, the health of the optic nerve, and the integrity of the retina. Many serious conditions — including glaucoma and early diabetic eye disease — can only be reliably detected through this kind of thorough clinical assessment.