More than 1,700 people in one town are at risk of losing their vision as a result of a common eye disease, according to a high street optician.

An estimated 1,708 residents living in Northallerton are at risk of developing glaucoma, which is claimed to be one of the world’s biggest causes of blindness.

The estimates were released by Specsavers, through statistics held by the RNIB, as Glaucoma Awareness Week began on Monday.

Michael White, ophthalmic director at Specsavers in Northallerton, said: “There are several factors which can increase your risk of developing glaucoma such as a family history of the disease.

“Other risk factors would include those who have black-African or Asian heritage as well as those who have higher levels of short sightedness.”

Researchers believe glaucoma occurs when natural build inside the eye does not drain properly, which leads to a build-up of pressure.

The build-up of pressure then causes damage to the optic nerve and nerve fibres from the retina.

Mr White said the disease can be treated if detected early.

He said: “With the most common form of glaucoma, visual loss is initially very subtle, affecting mainly the peripheral vision rather than central, which can make it harder to notice.

“Some forms of glaucoma are more rapid with a sudden painful build-up of pressure in the eye which produces blurred vision and haloes around lights, but they are less common.”

The optician said eye tests, which can detect early signs of glaucoma, should be taken every two years.

Karen Osborn of the International Glaucoma Association said: “We regularly hear from people who have permanently lost sight to glaucoma because of late diagnosis. People are often angry and upset to learn that simple regular visits to their local high street optometrist could have detected the condition. The earlier treatment starts, the more likely that someone will retain useful sight for life, so it’s great that so many Specsavers’ are on board with Awareness Week.”