Cataracts and Surgery
When the lens in the eye becomes cloudy and vision is affected, it is likely to be due to cataracts. Most cataracts are related to aging and it is a very common condition in older people. A cataract can occur in either eye, or both eyes. It cannot spread from one eye to the other.
In a healthy eye, light passes through the cornea and the pupil to the lens. The lens focuses the light, producing clear, sharp images on the retina at the back of the eye. As a cataract develops it scatters light, preventing a sharply defined image from reaching the retina.
At first, the cloudiness may affect only a small part of the lens and may not be noticed but over time the cataract grows larger and deeper in colour.
When a cataract reaches the stage where it significantly scatters or even blocks light, vision becomes impaired and cataract surgery is usually recommended to restore vision. The surgeon will remove the clouded lens and in most cases replace it with a clear plastic intraocular lens.
Types of Cataracts
Although most are related to aging, there are other types of cataract:
• Secondary cataracts can form after surgery for other eye problems, such as glaucoma.
• Cataracts also can develop in people who have other health problems, such as diabetes. They have also been linked to steroid use.
• Traumatic cataracts can develop after an eye injury, sometimes years later.
• Cataracts in babies, or congenital cataracts, may be present at birth or develop in childhood, often in both eyes. These may be so small that they do not affect vision, however, if they do the lenses may need to be removed.
• Radiation cataracts can develop after exposure to some types of radiation.
What Causes Cataracts?
The lens lies behind the iris and the pupil and works much like a camera lens. It focuses light onto the retina at the back of the eye, where an image is recorded. The lens also adjusts the eye’s focus in order to see things clearly both up close and far away. The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear and allows light to pass through it.
In the aging process, the structure of the protein fibres breaks down and some of the fibres may clump together and start to cloud a small area of the lens, forming the cataract. Over time, the cataract may grow larger and cloud more of the lens, interfering with vision.
Other risk factors include diabetes, smoking or excessive exposure to cigarette smoke, eye injury or inflammation, eye surgery, exposure to UV light and a family history of cataracts.
How Do Cataracts Affect Vision?
When a cataract is small, the cloudiness affects only a small part of the lens without causing any noticeable change in vision. Cataracts tend to “grow” slowly, so vision gradually worsens. Over time, the cloudy area in the lens may get larger, and the cataract may increase in size. Seeing may become more difficult and vision duller or blurrier.
Clouded vision can make it more difficult to do everyday activities such as read, drive a car or see the expression on a friend’s face. Looking through a cloudy lens is like trying to see through a fogged-up window. Cataracts can affect distance vision and cause problems with glare, halos around lights, and fading or yellowing of colours.
Since the clear lens slowly changes to a yellowy brown colour, it adds a brownish tint to vision. At first, the amount of tinting may be small and may not cause a vision problem. Over time, however, increased tinting may make it more difficult to read and perform other routine activities. This gradual change in the amount of tint does not affect the sharpness of the image transmitted to the retina but advanced lens discoloration leads to colour distortion, making it difficult to distinguish between darker colours like blue, purple and black.
Who is at Risk for Cataracts?
The term “age-related” is a little misleading. People can develop age-related cataracts in their 40s and 50s. These are mostly small and do not affect the eyesight. It is after the age of 60 that most cataracts begin to steal vision.
Other risk factors for contracting a cataract include certain diseases, such as diabetes and personal behaviour, such as smoking and alcohol use. Prolonged exposure to sunlight can also promote cataracts.
How do I Protect My Vision?
Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay the onset of a cataract. Stopping smoking is advisable. Researchers also believe that good nutrition can help reduce the risk of age-related cataracts, recommending a diet of green leafy vegetables, fruit, and other foods with antioxidants.
Symptoms and Detection
The most common symptoms of a cataract are:
• Clouded or blurry vision.
• Faded colour vision.
• Glare, where sunlight or artificial lights may appear too bright. A halo may appear around the light.
• Poor night vision.
• Double vision or seeing multiple images in one eye, though this symptom may resolve as the cataract increases in size.
• Frequent prescription changes in your eyeglasses or contact lenses.
These symptoms also can be a sign of other eye problems so it is advisable to have a full eye examination at Insight Optometrists if any of these symptoms are present.
How is a Cataract Detected?
Cataracts are detected through comprehensive eye examinations. Insight Optometrists have state-of-the-art testing equipment to examine the eye thoroughly, both internally and externally.
The early symptoms of a cataract may be improved with new eyeglasses, brighter lighting, anti-glare sunglasses or magnifying lenses. If these measures do not help, surgery is still the only effective treatment. Cataract surgery involves removing the cloudy lens and replacing it with an artificial lens.
Regular vision tests can check for cataracts as well as other vision disorders.
Book your eye examination with Insight Optometrists today.
1. ‘All About Eyes’ newsletter published by the Optometrists Association Australia (OAA) and reproduced here with kind permission.
2. Health Direct – Health Information and Advice: Cataracts