How you can live in harmony in today's 'mixed' practices
Q My husband is a teacher and I'd like to know the current evidence of hazard to eyesight from interactive whiteboards.
A There has been recent concern regarding possible eye damage from 'interactive whiteboards' or more accurately from the projectors used with them. After initial anecdotal reports, the Health and Safety Executive has said the projectors can 'expose the eye to levels above one of the exposure limits which HSE uses as a guide for compliance with applicable legislation' (www.hse.gov.uk/ radiation/nonionising/whiteboards.htm)
There seems little doubt that staring directly into the projector beam for more than 20 seconds can potentially cause damage to the retina. However, in a similar way to looking at the sun, the discomfort from doing this prevents no more than a brief look.
Although the HSE goes on to say the exposure limits are not statutory, it has published good practice guidelines for employers in the education sector:
·Avoid staring directly into the projector beam.
·Minimise the amount of time facing toward the beam. Users are advised to keep their backs to the beam as much as possible. In this regard, the use of a stick or laser pointer to avoid the need for the
user to enter the beam is recommended.
·Employers should also try to ensure projectors are located out of the sight line from the screen to the audience. This ensures that, when presenters look at the audience, they do not also have to face the
projector lamp. The best way to achieve this is by ceiling-mounting rather than floor or table-mounting the projector.
Further guidelines are given by the British Educational and Communications Technology Agency (www.becta.org.uk/leaders/ leaders.cfm?section=3_1&id=3173).
These are generally the same as the above but add:
·A maximum of 1,500 ANSI lumens is normally adequate for projection equipment in most classroom environments. The only exception might be very bright lighting conditions. In this case the advice is to use window blinds rather than increasing the brightness of the projector.
·When purchasing or using a projector for purposes when it is likely that a person will be standing in front of the beam, consider using a method of brightness reduction such as a neutral density filter or brightness adjustment facility.
Both of these bodies suggest that there is minimal risk to eyesight if these recommendations are followed.
Mr Scott Fraser, consultant ophthalmologist, Sunderland Eye Infirmary