Cataract is a clouding of the crystalline focusing lens inside your eye.
It is a normal part of aging and almost everyone will get some degree of cataract if they live long enough, though some people may not notice any symptoms.
Symptoms of cataract include blurry vision, glare, halos, change in glasses prescription, difficulty reading fine print and difficulty driving at night. Trouble seeing up close without glasses after your mid 40s is not caused by cataract, but is a condition called presbyopia which is a hardening of the focusing lens so that it can no longer focus up close. Treatment for this is reading glasses or refractive surgery.
Many people believe that a cataract is a growth across the surface of the eye which you can see, but it is actually a clouding of the internal lens behind the pupil (the black circle in the middle of your eye). It is not possible to see a cataract from the outside unless it is very advanced so the best way to be get the correct diagnosis is to see your eye care practitioner – either an optometrist, your GP or a specialist ophthalmologist.
Thankfully cataracts are almost always easy to permanently fix with a simple, safe and painless operation.