Drivers warned of undiagnosed glaucoma

Glaucoma Australia says the illness causes one eye to compensate for the other, making the loss of sight difficult to detect in its early stages.

Opthalmologist Stuart Graham says only half of glaucoma sufferers have been diagnosed.

"It doesn't encroach like a black tunnel," he said.

"It has a sort of effect of having just a neutral loss of peripheral field and you're not really aware of it.

"Then all of a sudden you start bumping into things, and of course that has major implications for people who are out there driving cars."

Dr Graham says people with glaucoma may not know they are losing their sight because one eye compensates for the other.

He says drivers with glaucoma often see perfectly well in the the distance but miss objects up close and side on.

"Say for instance a pedestrian, a child, runs, steps out from the curb and they have a blind spot, an enlarged blind spot in their peripheral, mid-peripheral vision," he said.

"They might not see that person till it's too late.

"It has implications for missing signs and things like that." © 2007 Australian Broadcasting Corporation