New England College of Optometry - Scope Yearbook (Boston, MA)

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Good Light and Good Eyes Must Be Partners Samuel G. Hibben Director of Apjnlierl Liglzting Il C'SffllglIOllSL' Electric Corporation, Bloonzfielfl, N. j. Modern seeing tasks usually demand a greater expenditure of seeing energy and place a greater burden upon the visual or- gans. This comes about through longer hours spent under artificial illumination: from the changing and flickering types of backgrounds and of objects in the field of view: from the high speed tempo of modern living and from the needs of keen visual acuity both at work and at play. There have been many changes in arti- ficial illuminants and in their methods of application in this decade. Today's light sources are generally capable of producing a greater volume of light and while in them- selves they are usually not brighter per unit area than in former days yet they are used in greater abundance and consequently may re- quire better shielding and shading and a more careful control of the direction of the light. Also today's lamps are capable of pro- ducing a wide variety of colors and they may even possess different qualities of radiation. including the infrared and ultraviolet ener- gies. Every optometrist knows that the eye is a wonderfully adaptable organ, capable of reg- istering the sensation of vision over a tre- mendous range from at least that of full June sunlight of 10,000 footcandles on the target. to the detection of a candle flame seen at the distance of 10 miles. NVe recall that in lf1000 of a second the eye can detect a light source and that in spite of this speed of ac- tion, the human eye is quite similar to the camera in that the pupillary opening may change its area over a range of l to 16 and that the eye may take either time-exposure pictures or instantaneous snapshot pictures. depending upon the illumination of the tar- get. Also we recall that at the age of 20 the area of the pupil may be double what it is at the age of 60, plus many other changes and variations all of which should be ap- praised along with the quantity and quality of the light required. The eye is perhaps to a dangerously large degree an uncornplaining organ. WVe do not know definitely just what physiological changes occur after months or years of seeing under bad illumination but there certainly is satisfying evidence that good lighting can relieve much of the strain and much of the discomfort of seeing and that bad lighting aggravates almost all of the deficiencies of the eye. The best eyes in the world cannot do a good job without good illumination. By good illumination we mean: l. Sufficient footcandles for an ordinary target, generally on the order of at least 25 to 50 for reading common type and printing or upwards of 10 for viewing large stationary objects. Very fine and very dark objects may require considerably more footcandles. 2. The brightness of the target must be considered, meaning that not only should the illumination falling upon it be adequate, but that its ability to reflect light is ample. In this connection comfortable vision suggests a contrast ratio of brightness as between the immediate task and its surrounding back- ground of not much greater than 3 to l. 3. Almost axiomatically the light should be steady and the target or the task should not vibrate or fluctuate in brightness. At least the quantity of light should not change more rapidly than can the pupillary opening. 4. Common glare such as from bare or badly shielded lamp bulbs or from brilliant PAGE ELEVEN

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R OPTICAL CO., INC. GENEVA. N. Y. Since 1864 ll lCIlIIflIg'III.lIl11l- fncluwr of Slylrd Eyvzuear, Qualify Beyond Question Lenses and Lens Proccssin EQllf1Jl'H.6'IIf for Hu' Optical L,IlbOTlIlO7'lV

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reflections in polished metal, glass table tops, shiny black typewriters or from any targets that act like mirrors will unquestionably place a tremendous and unnecessary strain on the eyes. Many people confuse the brightness of the source with the amount of comfortable illumination required. Sometimes where the illumination seems inadequate, a bigger or brighter lamp bulb in the field of view will result in poorer vision, not better. 5. Todays illuminants can do a much better lighting job than has ever been done heretofore, but like any sharp tool our light source must be handled with intelligence and used carefully lest they do damage as well as good. The worthy optometrist has a responsi- bility to prevent and guard against deficien- cies of vision as well as to alleviate and cure them. He can be a valuable Councilor and guide for the thoughtless person who can often secure much better lighting with very little effort. Far too many of our lighting fixtures today are either too bright or are hung too low or are improperly placed in re- gard to shadows and reflections or become inefficient due to dirt and neglected main- tenance, or may be terribly handicapped by dark colors of interior paint and surround- ings. All these and many other factors de- mand that good eyes and good light form a firm and lasting partnership. VISION DEVELOPMENT QC0nlinued from page 9D see-pic-screen-video age. This problem includes the care of the visually handicapped: prevention of indus- trial, highway, and household accidents: the reduction of illiteracy: vocational selection and training: important aspects of mental health and personality in adultsg and above all, the developmental welfare of growing children of preschool and school age? TO THE GRADUATING CLASS OF 1950 OUR CONGRATULATIONS Wilson 6- Halford Optical Co. 387 WASHINGTON STREET BOSTON 8, MASS. PAGE TWELVE