More than 35 per cent of the population will be visually impaired by 2020, a Midland charity has warned.

According to the Sedgleybased Beacon Centre for the Blind, nearly two million people in the UK are already registered blind or partially sighted and the Government is expecting this figure to rise in 15 years because of links with smoking, diabetes, age-related illness and general poor health.

The centre's capital appeals officer Kate Fletcher said one of the main reasons for eyesight deterioration was agerelated macular degeneration, AMD, which is a retinal eye disease, causing progressive loss of central vision. It is the leading cause of blindness in the UK.

AMD can be hereditary but early detection and treatment can lessen its impact.

But a series of studies between 1996 and April 2005 had all come to the same conclusion about the effects of smoking on eyesight,

regardless of age. "Most people are under the misapprehension that sight deterioration is something over which they have no control, especially as they grow older," she said.

"It is true that our eyes change with age and that most visual impairment is acquired later in life, however as with any disease, positive steps can be taken to protect our eyesight and lessen the risk of serious sight impairment later on.

"The strongest and most important message regarding protection against AMD is do not smoke. Those who smoke are twice as likely to develop AMD than those who do not, yet until very recently very few people were aware of the links between smoking and sight loss."

The estimated cost of care for blindness in the country is £4.9 billion per annum, but Ms Fletcher said steps could be taken to limit the risk of serious sight impairment and therefore reduce the costs.

She said: "In recent years, deaths from certain forms of cancer have been radically reduced due to regular screening. In the same way, regular eye tests will reduce the incidence of blindness in later life.

"There are also a number of avoidable risk factors that individuals can control. One way in which we can protect our eyes is by limiting exposure to bright light.

"There is evidence of an increased incidence of sight deterioration in people who spend long periods in the summer sun, so wearing sunglasses at midday to protect your eyes is advisable.

"Obesity and high blood pressure have also been linked to eye impairment, so it is sensible to control body weight, blood pressure and cholesterol levels.

"The impact that diabetes has on sight-impairment is considerable. Cataracts are twice as common in people with diabetes and most diabetics will develop some form of retinopathy, a condition which, if not diagnosed will cause irreparable damage and in many cases blindness."

Birmingham optometrist Waqar Salim said he had always made a point of highlighting the link between smoking and visual impairment to his patients, who often do not realise the damage they are causing to their eyes.

Mr Salim said: "From my knowledge and experience, patients who smoke have an increased risk of certain conditions related to visual impairment. Smoking is a risk factor for glaucoma and cataracts. I tell them if you stop smoking, it will reduce the risk."