A cataract is clouding or opacity of the lens inside the eye. It causes gradual blurring of vision and often glare

What is a cataract?

A cataract is clouding or opacity of the lens inside the eye. It causes gradual blurring of vision and often glare. In a normal eye this lens is clear. It helps focus light rays onto the back of the eye (the retina), which sends messages to the brain allowing us to see. When a cataract develops, the lens becomes cloudy and prevents the light rays from passing onto the retina. The picture the retina receives becomes dull and fuzzy. A cataract usually forms slowly and most people experience a gradual blurring of vision.

What causes cataracts?

Most forms of cataract develop in adult life. The normal process of ageing causes the lens to harden and become cloudy. This is called an age-related cataract and it is the most common type. It can occur at any time after the age of 40. Although most cataracts are age-related, there are other types, including congenital (present at birth), drug induced (steroids), and traumatic (injury to the eye). Cataracts are also more common in people who have certain diseases such as diabetes.

What are the symptoms of cataract?

Cataracts usually form slowly over years causing a gradual blurring of vision, which eventually is not correctable with glasses. In some people the vision can deteriorate relatively quickly. Developing a cataract can also cause glare, difficulty with night-time driving and multiple images in one eye which can affect the quality of the vision.

Diagnosing a cataract

Cataract is often diagnosed in primary care by an optician or GP during a routine eye examination.

At your initial appointment with Moorfields, you will undergo eye tests and an optometrist will assess your eye prescription. A full medical history will also be taken to ensure you are suitable for treatment.

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