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The New Zealand Railways Magazine, Volume 11, Issue 11 (February 1, 1937)

Eye Strain And Electricity

Eye Strain And Electricity.

I don't always believe what I read in the papers, but a report published in the English press of a demonstration staged by the Electric Lamp Manufacturers' Association of Great Britain put forward some sensible assertions, the principal of them being that through the electrician and the optician the eyesight could be efficiently preserved.

An interesting address dealt with the measurement of light under which we use our eyes. Just as we speak of a “degree” as the term of measurement for heat, light is measured in “foot candles.” The pertinent part of the speech, to my mind, was this: “Sunlight on the lawn in midsummer would measure 10,000 foot candles; in the shade of a tree it would be reduced to 1,000 foot candles; under a verandah it would fall to 500 foot candles, and close to a window something like 200 foot candles. But at night, after the sun had set, we drew up an easy chair and with a 60 to 100 watt lamp got no more than 5 foot candles.”

Obviously, then, the illumination in most of our homes needs to be increased. The placing of lights has improved considerably, though many people still endeavour to carry out eye-work with the aid of one central bulb in a room. For reading or sewing, you see a comfort-loving and sensible member of the household pull up a chair so that he or she can sit with the light behind and a little to one side. Unthinking younger members, or unfortunate visitors flop on any handy seat and do their best with the illumination that reaches them.

Many people hesitate to instal stronger light bulbs in their homes for fear of incurring heavier bills. If only the economical person realised the danger to the eyes of inferior illumination, she (it is usually a she) would change the bulbs immediately.

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