Through out history cataracts have been the most feared eye condition. Although it was one of the few blinding conditions for which there was a medical intervention, the 'cure' was hazardous, painful and highly unlikely to restore good vision.
Today there is no medical treatment that will stop the development of a cataract. Although current research does suggest that a good diet and protection from UV are important in delaying the stage at which a cataract will need to be operated on. However because they are the commonest eye condition that requires surgical intervention, modern ophthalmic surgeons have become very proficient at restoring good visual function.
Cataracts are not a sign of a diseased eye: most cataracts are just a sign of an aging eye. They only need dealing with when they stop an individual from doing what they want to do, which nowadays usually means driving. A developing cataract usually causes a gradual change in vision (though some can progress quite quickly). Unfortunately just as it makes it difficult for a patient to see out clearly, so it also makes it difficult for the optometrist to see in clearly. This makes it harder to be confident that poor vision is the result of cataract and not something more serious. One good reason for having regular eye examinations by the same optometrist, or at least at the same practise is that your optometrist will have access to your previous records.
When cataracts cause cloudy vision, your community optometrist may want to do additional tests. This can mean you need a longer appointment or to return on another day to have dilating drops put in your eye. The drops are not painful but can give you blurry vision for several hours, so you may not be able to drive home. Some tests that your optometrist may want to do, may not be funded by your NHS eye test, so you may be asked to pay a private fee. Your optometrist should explain all this before continuing. These tests can be useful as they may avoid unnecessary visits to hospital clinics.
If your optometrist decides that the cause of your poor vision is a cataract and that spectacles will not give you the vision you want then s/he will offer you the choice of doing nothing or being referred to a Hospital Eye Department for cataract surgery. You should be certain that you do want surgery before being referred, but sometimes your ophthalmic surgeon will decide you need a while longer before having cataract surgery. If an NHS surgeon does not believe your cataract is bad enough to justify surgery, but you feel it is you can always look into having it done privately.