Clearing the fog: Cataracts explained

Cataracts, a common eye condition, occur when the natural lens in the eye becomes cloudy, leading to blurred vision. But how prevalent are they, and can they cause blindness? In her latest online article, Miss Francesca Harman delves into the basics of cataracts, including their symptoms and the effectiveness of cataract surgery.

What are cataracts?

Cataracts are a condition in which the natural crystalline lens inside the eye becomes progressively more cloudy or opaque. The clouding blocks light from passing through to the retina, resulting in misty vision.

How common are cataracts?

Cataracts are the leading cause of blindness worldwide with the incidence increasing with age, becoming very common over the age of 70. Some people develop cataracts earlier than others, but they are an inevitable fact of ageing.

They usually develop gradually and are typically caused by prolonged ultraviolet exposure from sunshine over many years. They can also occur at a younger age, due to other factors such as trauma, diabetes, severe intraocular inflammation or prolonged steroid use. They can also sometimes be inherited.

Can they cause blindness?

The longer they are left to develop, the greater the effect on your vision. If they are left untreated, they may eventually lead to blindness although it is unusual to reach that stage in the UK. Thankfully they are treatable with a simple and safe procedure, with the vision returning to normal after surgery.

How do I know if I need cataract surgery?

Cataract symptoms depend on the size and density of the cataract, where it is in the eye and if both eyes are involved or not.

Symptoms may include:

• clouding or blurring of vision, for example finding it harder to read, sew or watch television
• sensitivity to light and glare, particularly car lights at night
• seeing colours as faded or sepia-toned
• occasionally seeing double images

Cataract surgery is indicated when the cataracts become developed enough for the blurring to interfere with daily life. Once daily activities are affected or limited, for example difficulty reading even with glasses on, then surgery is indicated to improve the vision.

Is cataract surgery a major procedure?

Cataract surgery is a highly successful treatment option and is the most commonly performed operation in the UK. It results in the highest increase in quality of life of all procedures.

The procedure, known as phacoemulsification, takes about 30 minutes in total and is usually performed under local anaesthetic. An ultrasound probe gently breaks down the cloudy lens from within the capsular bag it is held in, then an artificial plastic lens is inserted into the bag to allow clear, focused vision.

Cataract surgery is not a major procedure in that you will feel physically fine afterwards with a rapid visual recovery, but it involves precision surgery within the eye and should not be counted as a minor procedure.

Will cataract surgery hurt?

The vast majority of cataract operations are performed under local anaesthetic, either an injection below the eye (which stings for a few seconds) or just drops in the eye. Patients can be aware of a feeling of pressure sometimes, and fluid running on the face, but they should not experience any pain.

Post-operatively the vision can be blurry for the first few days, and occasionally the eye can feel irritated or dry initially.

Miss Francesca Harman is an esteemed ophthalmologist. You can schedule an appointment with Miss Harman on her Top Doctors profile.