A study conducted by the British Medical Journal Many suggests that aged people could be prevented from falls, if they avoid wearing varifocal glasses while moving outdoors.

According to the study, 40% falls could be avoided if single-lens glasses were worn outside.

It is said that Varifocal lenses are extensively prescribed because they rectify far and near sight problems in one pair of glasses.

Although, the Australian study says that they might cause problems impairing balance.

This study of the threat of falling over, while wearing varifocals has been conducted earlier and is also called multifocals or progressives.

But this risk has to be offset against their benefits when it comes to carrying out tasks that require changes in focal lengths, like driving, shopping and cooking.

The authors recommended, on the basis of the findings that aged people who have an active outdoor routine should be suggested that regardless of the trouble they should exchange between single and varifocal glasses.

Although the study was welcomed by the UK's College of Optometrists they also emphasized that a lot of people did find it annoying to have two pairs of glasses.

"However, everyone is different and we are pleased that the report highlights another factor that can be taken into account when deciding which type of lens is best for the individual person's needs," said the college's advisor, Dr. Susan Blakeney.