SINGAPORE- Instead of merely asking to test how well you can see, you should ask for a more comprehensive eye health check the next time you visit a spectacle shop, say experts.

An eye health check involves checking the front and back structures of the eye to make sure they are healthy. Early signs of sight-robbing eye diseases such as cataract, glaucoma or age-related macular degeneration can be detected through these tests.

"When people go to a spectacle shop, they usually expect the staff to check their myopia and prescribe new glasses," said Singapore Optometric Association (SOA) president Koh Liang Hwee. "More often than not, the shop will have an optometrist who is trained to perform more comprehensive checks."

These checks are important, given that some eye diseases like glaucoma barely show any symptoms until the acute stage, he said on the sidelines of the 5th Asean Optometric Conference on Thursday.

"The public should know that poor vision may not be only caused by myopia or presbyopia, but by eye diseases that can be detected through these checks," Dr Koh said, referring to short-sightedness and another condition in which one cannot focus on near objects. Most of the time, the cost of eye health checks are waived when customers buy glasses or contact lenses, he added.

The Singapore public may not be as familiar with the concept of eye health checks as optometry is a relatively new discipline in Singapore, said SOA councillor Chui Wen Juan. Optometrists, who do these eye health checks, differ from opticians who mainly prescribe and dispense glasses. "In other countries like the United Kingdom, where optometry is a more established discipline, people expect these eye health checks," she said. All spectacle shops that sell contact lenses should have an optometrist.

Still, they are less common than opticians - there are an estimated 2000 opticians in Singapore and about 600 optometrists.

Retiree John Lim, 58, was glad that he was given an eye health check when he went to buy a new pair of glasses to correct his blur vision.

It was found that his blur vision was not caused by worsening myopia but by a detached retina instead. Mr Lim had to go for surgery to correct the condition.

"I'm really glad the optometrist checked my eyes thoroughly, it really saved my sight," he said.