TINTED GLASSES

New Zealand Listener, Volume 8, Issue 187, 22 January 1943, Page 14

TINTED GLASSES

| (Written for "The Lis-

| tener" by DR.

H. B.

TURBOTT

Director of

the Division of School Hygiene)

OW that summer is established, + quite a number of people are wearing tinted glasses, so much so that one wonders whether most of these are necessary or merely a fashionable fad. The eye specialist doesn’t often prescribe them, the reasons for their use being strictly limited. In industrial life, wherever there is the flash of short-circuiting powerful electricity, tinted glasses will be essential. We have become accustomed to the goggles worn by welders. In modern warfare, tinted glasses have become necessary equipment for that part of the personnel carrying out. aero-plane-spotting, whether in the navy, army or air force, A favourite approach to a target is with the sun behind the aircraft and the sun’s direct rays on the objective. Anti-aircraft spotters, and any civilians who look at the sun with unprotected eyes will get an inflammation of part of the retina. The infra-red and visible rays actually burn the retina at the spot on which the rays converge and focus. The delicate lining is destroyed and replaced by scar tissue; the damage is permanent and blurred vision results. There have already been cases of permanent eye damage in the Allied services, whose personnel failed to use protective devices, or were supplied with something that proved defective in use. War pensions have had to be awarded, and active personnel lost, for an injury that was preventable, Many Makes and Many Tints The usual preventive measures are the wearing of tinted glasses, or the use of binoculars fitted with filters, or of screens of tinted glass. Tinted glasses are not’ all standardised. There are many makes and many tints. They should be graded according to their power to absorb both infra-red and ultra-violet radiations, so that weak and sometimes useless glasses should not be offered for sale. In one Allied navy, which has had casualties from imperfect protective glasses, Crookes B2 tinted glass is now used. This is a glass incorporating certain metallic oxides that absorb heat, visible, and ultra-violet rays without cutting off too much light for clear vision. This glass is standardised, . To return to civilians and tinted glasses, these should not be worn because they seem to be fashionable. A visit to an eye specialist will soon determine whether you need to enhance your appearance with tinted spectacles. For most people they’ are unnecessary, except, perhaps, when doing much motor driving over brightly-lit summer roads, or when holidaying in the snow-covered mountains, or sunbathing day by day at the light-reflective beaches. If you won’t seek the advice of an eye specialist and will wear tinted glasses, then at least see that the tinted spectacles you buy are of standardised, properly protective glass that will shield and yet give the maximum: light.