Blindness is the condition of lacking visual perception due to physiological or neurological factors. Various scales have been developed to describe the extent of vision loss and define blindness.
Total blindness is the complete lack of form and visual light perception and is clinically recorded as NLP, an abbreviation for "no light perception. Blindness is frequently used to describe severe visual impairment with residual vision. Those described as having only light perception have no more sight than the ability to tell light from dark and the general direction of a light source. When someone is partially sighted, they have a less severe loss of vision.
Blindness can cause difficulty with almost every aspect of life, especially everyday tasks such as cooking, dressing, reading and writing, shopping and going for a walk.
Visual problems may also cause huge problems for children at school. However, although baby’s eyes are tested, many schoolchildren don’t have regular sight tests even though some eye conditions set in as the child grows. As a result children may strain to see, read or contribute in class and their progress may be limited by undetected visual problems.
The risk of physical and social isolation is greater for people who are blind or partially sighted as it can be difficult to get out and make new friends. Blindness can also be an expensive condition because of the cost of special equipment.
Causes of blindness
Many different things can damage sight. Accidents and disease are often responsible for blindness, while some people are born blind or partially sighted because of genetic or developmental disorders.
Common causes in adults include age-related macular degeneration, cataracts, retinal detachment, diabetic retinopathy and glaucoma. While not causing blindness, common visual problems such as short-sightedness, squints or long sight may give a child particular problems at school.
There are a range of support services, charities, and devices that can all help make life easier if your vision is impaired. And just because you have low vision, it does not mean you are no longer able to work.
With the help of assistive technology, training and support, many people who are either partially sighted or blind can continue to work in often very demanding roles. Probably the most well-known example of such a person is the politician David Blunkett.
Some causes of blindness can’t be prevented but there are things that you can do to reduce some of the risks.
If you develop problems with your sight, or symptoms of eye disease such as pain, visual changes or a discharge, then get urgent medical advice.
If you have a condition such as diabetes, glaucoma and cataracts, which are known to damage sight, then it is especially important to look after your eyes. Treatment may help to preserve vision.
Most sight loss in diabetes is preventable but waiting until vision has deteriorated before seeking help may be leaving things too late. Although their vision may seem fine, people with diabetes can unknowingly develop changes in the retina which can cause permanent damage if not treated. People with diabetes are advised to have annual eye tests, which are free for them, as they are for anyone with any kind of disability.
If you wear contact lenses then you should scrupulously follow instructions for their use, including good hygiene in handling the lenses, and seek urgent medical advice if you develop any problems.
Research suggests that the following points will make sure your eyes are healthy and your risk of developing an eye condition is as small as possible.
Everyone should have their eyes examined at least once every two years - even if there is no change in your vision. An eye examination can often pick up the first signs of an eye condition before you notice any changes in your vision. This can lead to you getting vital treatment at the right time, which could save your sight.
Did you know smoking can double the risk of developing age-related macular degeneration, the UK's leading cause of sight loss? In fact, the link is as strong as the link between smoking and lung cancer. You definitely should speak to your GP about giving up smoking.
Eating a diet low in saturated fats but rich in green leafy vegetables such as spinach and broccoli may help protect against cataracts and AMD. Oranges, kiwis, nuts & nut oil, seeds and oily fish may also help prevent and slow down some eye conditions. Taking supplements is not a substitute for a healthy diet. It is important to maintain a healthy weight. Obesity can increase the risk of developing diabetes, which in turn could lead to sight loss.
UVA and UVB rays in sunlight can harm your eyes and may increase the risk of cataracts and AMD. In bright sunlight it is important to wear sunglasses, glasses or contact lenses with built in UV filter to protect your eyes. You should only buy sunglasses that have a CE mark or carry British Standard BSEN 1836:1997 otherwise you cannot be sure that they will adequately protect your eyes from the harmful rays of the sun.
DIY causes thousands of elevated injuries each year. Always wear safety goggles to protect your eyes from flying debris and fine particles. Sport (especially racquet-based sports) also causes lots of eye-related injuries each year. Investing in a good pair of protective sports goggles will help prevent serious damage to your eyes.