The term 'cataract' refers to clouding of the normally clear human lens which most often occurs with age. There is no known (or proven) way of preventing cataract from developing.
The normal human lens focuses light rays onto the retina. The retina acts like the film of a camera and receives these rays and sends the messages back to the brain via the optic nerve (picture). Significant cataract blocks and distorts light passing through the lens, causing visual symptoms.
Cataract does not suddenly appear but takes time to develop. Usually this means years but occasionally it may get worse in a matter of months. Opticians often tell people they have cataract even when they have no symptoms and in general, cataract only needs treatment when it begins to cause problems with the sight.
Symptoms of cataract
Having cataracts is often compared to looking through the dirty lens of a camera. Cataracts may cause a variety of visual changes, including blurred vision, difficulty with glare (often with bright sun or car-lights), decreased color vision, increased nearsightedness accompanied by frequent changes in eyeglass prescription, and occasionally double vision in one eye.
Some people notice a phenomenon called "second sight" in which one's reading vision improves as a result of their increased nearsightedness from the increased density of the cataract. A change in glasses may help initially once vision begins to change from cataracts. However, as cataracts continue to progress, vision becomes blurred and stronger glasses (or contact lenses) will no longer improve sight.
The only treatment for cataract is surgery. The standard cataract surgical procedure is a process called phacoemulsification. With the use of an operating microscope, a very small incision is made in the surface of the eye (the cornea). A small probe is inserted into the eye that uses ultrasonic vibrations and suction to emulsify and remove the cataract. The skin of the old human lens is left in tact to support the artificial lens, made of soft plastic. This artificial lens is essential to help your eye focus after surgery.
Anaesthesia for cataract surgery
The surgery is most commonly performed under local anaesthetic. Traditionally patients have a sharp needle injection around the eye known as a peri-bulbar block. Mr Rossiter is experienced in a no-needle technique known as topical anaesthesia. In this method, drops are used to numb the cornea and anaesthetic is placed into the eye as part of the first step of the operation. More apprehensive patients may choose the comfort of a general anaesthetic if fit and well.