The University of Hong Kong and the NGO Orbis said on Monday that they would be carrying out Hong Kong's first large-scale eye screening project for glaucoma.

More than 3,000 public housing tenants aged 50 or above in Kwun Tong, Tai Po and Southern District will be selected at random and invited to undergo free eye tests with an ophthalmologist, with patients needing treatment to be referred to public or private clinics.

Christopher Leung, who chairs the university's department of ophthalmology, said they will be seeking to identify people with macular degeneration who are more likely to lose their central vision.

"If patients after the screening, [their] macular are not affected, and the damage is relatively mild and the rate of change is relatively slow, these type of individuals can probably be monitored less often and the treatment can be less aggressive," Leung said.

The President and CEO of Orbis, Derek Hodkey, stressed the importance of early detection of glaucoma, describing it as "the world's leading cause of irreversible blindness".

"Tragically for sufferers, vision stolen by the condition can never be restored," Hodkey said.

He added that a new invention by the university, Retinal nerve fibre layer Optical Texture Analysis (Rota), will help provide ultra-accurate glaucoma checks.