Simon G Levy

Consultant Eye Surgeon
Reassuring Personal Care - Advanced Technology - Specialist Cataract and Refractive surgeon

In this article, I explain the causes and symptoms of cataract and how modern, ultra-small incisions and hi-tech lens implants treat cataract quickly and gently, restoring excellent eyesight.

What is cataract?

Cataract is a clouding of the lens of the eye. As the lens is no longer transparent, light cannot pass through it to reach the retina and vision deteriorates. In most cases cataract formation is simply a part of the ageing process like having grey hair.

Photo (left) of normal eye with clear lens (arrow). In a normal eye (right) light from object X is focused onto the retina

Photo (left) of eye with a cloudy cataract lens (arrow). In an eye with cataract (right) light from object X cannot reach the retina


Cataract usually causes gradual deterioration of vision, objects becoming less and less clear until eventually all sight is lost. Often more light than before is needed to see and to read. Colours may seem muted or yellow and there may be glare on a sunny day or when driving at night. Another symptom is increasing short sight, necessitating frequent changes in the glasses prescription. Cataract is usually present in both eyes although it may be more advanced in one eye.

Blurred vision caused by cataract (left) is cured (right) by surgery

Colors are less rich before (left) then after (right) cataract removal

The benefits of modern cataract surgery

Depending on the precise symptoms caused by your cataract, you may enjoy some or all of the following benefits of surgery:

  • Improved clarity of vision
  • Improved vision in dim light
  • Reduced glare on a sunny day or during night driving
  • Colours may seem richer
  • Improved vision may enable you to continue driving
  • Many studies have shown improved quality of life after cataract surgery. Activities such as reading, sports, cooking, driving, using a computer and sewing are generally easier after the operation. Even when the eye also suffers from other problems such as retinal disease, the remaining vision is usually improved by cataract surgery
  • The need to wear distance glasses may be less after cataract surgery. Some patients also become less dependent on reading glasses. This is so even when glasses have been necessary for many years
  • The phaco-emulsification technique is usually quick, safe and gentle to the eye and the recovery period is very short so that these improvements can be enjoyed quickly

When to have cataract surgery

Once cataract has begun it usually worsens with time as the lens becomes more cloudy. However the rate of progression varies greatly and cannot be predicted. Thanks to recent advances surgery may be performed as soon as the symptoms of cataract interfere significantly with your life. Having to wait until the cataract has ’ripened’ or ’matured’ is a thing of the past.

How cataract surgery is performed

Cataract surgery is performed by a key-hole technology unique to the eye, called phaco-emulsification. This is one of the best procedures of modern medicine. It is quick, taking only 15-20 minutes in most cases and has an outstanding safety record. The small incision is gentle to the eye and heals quickly without stitches. Recovery is so fast that most normal activities may be resumed the day after the operation.

1) Phaco-emulsification

An operating microscope designed specifically for eye surgery and delicate, miniaturised instruments are used. A keyhole incision only 2.2mm wide is made on the outside of the eye. A circular opening in the lens capsule exposes the cataract. Next the phaco-emulsifier is inserted. This sophisticated instrument uses high-speed ultrasound waves to break the cataract into tiny pieces which are suctioned out of the eye.

2) A lens implant

Removing the cloudy lens is necessary to allow light to pass to the retina. However to fully restore vision the focusing power of the lens must be replaced. This is achieved using an artificial lens made of plastic, called a lens implant.

3) The lens implant is injected

A lens implant is a very small focusing lens made of clear, medical grade plastic. Once implanted it will remain permanently inside the eye, requires no care and will not be rejected by the body.

4) The lens implant in place

Once implanted it will remain permanently inside the eye, requires no care and will not be rejected by the body. Read ‘Customised cataract surgery’ to learn how a modern lens implant maximises quality of vision and minimises glasses dependence.