Cornish artist Cecil Riley transfers his "visions" to canvas
Blind or partially sighted people in Devon and Cornwall may be experiencing vivid or frightening hallucinations as a side effect of their condition.
Charles Bonnet Syndrome is common among people with macular degeneration but can happen to anyone with severe sight loss.
It happens when the brain receives fewer visual images and replaces them with stored images or fantasy ones.
Doctors who diagnose eye disease are now being urged to warn patients.
The call has been made by the Macular Disease Society and the Royal College of Opthalmologists.
A number of people have been upset by the hallucinations - with some believing they were losing their sanity.
Mr Winified Amoaku, from the Royal College of Ophthalmologists, said some medical professionals had inadequate knowledge about the visual images.
"The hallucinations often involve seeing people's faces, landscapes, people or objects which aren't there, as well as patterns, grids and brickwork," he said.
The college has been working with the Macular Disease Society, and the Institute of Psychiatry to raise awareness of the syndrome and ensure patients are aware of the link.
Mona Makeig Jones, 88, from north Devon has dry macular degeneration.
She told BBC News first experience of disturbing visions had frightened her badly.
When she was going from her bedroom to the bathroom, her door appeared to be "choked with big black dogs".
"I hesitated then charged through and, of course, there was nothing there, she said.
"Then everything turned blood red - it was terrifying."
One woman was even referred for psychiatric treatment when she reported her visions.
But Cecil Riley from Marazion in Cornwall, who also has macular degeneration, has used his visions to create art.
"About six months ago I started seeing things. I wasn't frightened - I was disturbed, but also intrigued," the 91-year-old said.
"What I saw was like an eyeball with upper and lower lids, then red lines radiating around them from the centre."
Devon and Cornwall have about 10,000 people who are registered blind or partially sighted and it is thought up to 60% have or could develop the syndrome.