Most Australians are unaware of the dangerous times for sun damage to the eyes - and could be using sunglasses that do more harm than good, eye experts have warned.
With summer approaching, the Optometrists Association of Australia says harmful UV exposure to eyes peaks in the early morning and late afternoon, not in the middle of the day as previously thought.
It said that UV-protective sunglasses or prescription glasses should be worn from early morning to late afternoon, all year around, when outdoors or driving.
The OAA based its recommendations on a study by the Kanazawa Medical University in Japan, which found that ''peak UV exposure times for the eyes are not between 10am and 2pm, as has been believed … but between 8am and 10am, and 2pm and 4pm, for most of the year [except winter] because of the angle of the sun in relation to the eyes at those times''.
The authors said the results are applicable to several other countries including Australia.
In Australia, sunglasses must display a UV protection rating from category zero to four, with an alternative system giving an ''eye protection factor'' between one and 10.
Every pair with an EPF rating, no matter the level, offers equivalent protection to category two, three or four glasses.
The professional services manager from the OAA, Jared Slater, warned that lower-rated glasses were not sufficient - even though they met Australian standards.
''We want everyone to have category two, three or four glasses,'' he said. ''We're very good at protecting our skin but we need to start thinking about our eyes.''
Peter Meagher, a surgeon from the Royal Victorian Eye and Ear Hospital, also warned that some sunglasses may be contributing to the danger of eye damage.
''Small, dark lenses cause your pupils to dilate because they reduce glare,'' he said.
''It's possible this could allow more damage to the outer corners of the eyes .''
But Mr Slater said any level of protection was better than none.
The OAA said more than half of Australians are at risk of serious eye conditions - including cancer - because they are not wearing UV-protective lenses.
THE RIGHT PROTECTION
Ensure your sunglasses have a category two, three or four UV protection rating. (Every pair with an ''eye protection factor'', regardless of the rating, gives an equivalent level of protection.)
50 per cent of UV exposure comes from the back and sides so ensure your sunglasses have side protection and are close-fitting.
Eyes are vulnerable to UV damage at all times of the day, all year around, so wear glasses whenever you're outdoors or driving in daylight.
Broad-rimmed hats reduce radiation to the eyes by 50 per cent.
The tint does not indicate the protection level. Always check the label.
If you wear prescription glasses, consider adding a UV-protective coating.
Ensure your children wear protective glasses and put sunglasses with soft elastic straps on babies and toddlers.
Source: the Optometrists Association of Australia