GLAUCOMA is the leading cause of preventable blindness, yet if detected and treated early there is very little risk to sight.

So why does glaucoma cause so much blindness?

The International Glaucoma Association (IGA) is set to mark FROG week (For Relief of Glaucoma) next Monday to Sunday to raise awareness and try to prevent the condition before it's too late. Reporter Lisa Heritage spoke to resident Dorothy Crump, who has glaucoma, to

find out how it has

affected her life.

The 61-year old Ledwych Gardens resident first discovered difficulties with her vision at the end of 2002 when she was looking up at her illuminated clock in bed.

She was lying on her side, looking out of her left eye when she noticed the clock numbers had disappeared.

"At the time I just thought it was my blind spot and didn't think any more of it," she said.

"I later made an appointment with my optician who referred me to an eye specialist in February 2003.

"Six weeks later I took a visual field test but by that time, having left it so long, a good chunk of my vision had gone in my left eye and it had also affected the centre of my right eye."

By this time, it was too late to save Dorothy's vision. She was diagnosed with glaucoma and told the condition was irreversible. But she went to Birmingham for major surgery, called a Trabeculectomy, to ensure the condition did not affect her vision any further.

Dorothy said: "Unfortunately, in my case, the pressure was too high and eye drops would not have helped. My condition was too aggressive and I needed surgery to prevent the glaucoma from spreading.

"I had the right eye operated on last October and the left done last month. Unfortunately, this means I will never be able to continue with my love of swimming but, as my surgeon said, nothing comes without a price."

Dorothy is now keen that everyone goes for regular eye tests to check for signs of glaucoma. The three eye tests that should be taken are an ophthalmoscopy, a visual examination of the optic nerve; a tonometry, a check of the pressure within the eye and a perimetry, a check of the field of vision.

Often the condition is hereditary but in some cases like Dorothy it will creep up gradually and steal a person's sight without warning.

An IGA spokesman said: "Glaucoma gives no warning, it damages the off centre parts of the vision and generally starts in the one eye first. Loss of vision often goes unnoticed as the less affected eye "completes the picture" for the worse eye.

"A considerable amount of vision can be irretrievably lost before a person is aware of the problem. The further advanced the condition, the more difficult it is to treat effectively."

For more information about glaucoma, call 020 7346 5926.