Experts from the China Medical Association warned that the glare caused by bright light could harm eyesight and result in myopia.

And laboratory statistics show 43 per cent of students with myopia are victims of glare.

Glare can be described as direct or reflected light which can lead to "discomfort" or "disability".

Direct glare comes from the light source itself. Reflected glare brightens the object of visual attention, such as a computer screen.

"Discomfort glare" does not make seeing impossible, but it is uncomfortable. "Disability glare" disrupts vision and hides the image.

Glare can be a major threat to eyesight, leading to impairment of eyesight. "Glare has become a major source of light pollution," said professor Zhu Renyuan from the Ophthalmologist Laboratory under the Ministry of Health during a news conference held by 3M which recently launched new anti-glare lighting.

"Glare may not cause discomfort immediately. But exposure to glare over a long period can make vision blur and cause fatigue for the eyes and brains. A lack of efficiency in reading and writing can be expected, as well as headache and eye pain," he added.

The most comfortable angle at which to read a book is 58 degrees, but this is also an angle which can produce glare.

Lightbulbs of over 25 watts make the best choice for providing proper lighting for students. Lamp are preferable to light fittings and naked bulbs.

Tips to prevent unwanted glare:

1: Indirect lighting that throws more light upward than downward, diffusing the light and reducing glare on computer screens.

2: Parabolic louvers, special lenses or other diffusing media on fixtures that diffuse the fixture's light output, such as a kind of light by 3M which can diffuse the glare with a lens.

3: In an office, it may be possible to cut the ambient lighting system with reduced light output and diffusing media, while providing adjustable task fixtures at workstations.

4: Relocating the light source, relocating the task or changing its orientation until the glare is removed.

5: Changing surface reflection.

6: Using blinds or shades on windows to control the amount or angle of sunlight entering the work space.

(Shanghai Star  June 11, 2004)