Lighting for Children With Impaired Vision
By Norman B. Medow, MD, FACS
Children with impaired vision require well-lit rooms and play areas, both at home and at school, so that they may use their eyesight as effectively as possible. Lighting is always a primary, never a secondary, consideration. Even though a child's vision impairment may have already been addressed by the use of optical devices such as glasses, and the environment modified by color contrast and tactile features, lighting still plays a critical role in determining how well a child can see. Unfortunately, whether a room or other area is properly lit is often overlooked. When making decisions about lighting, it is important to consider amount, placement, ability to control, and glare reduction.
Glare is light that serves no visual function. There are two basic types of glare: reflected glare and scatter glare. Reflected glare occurs when light is focused on glossy surfaces. Glare from glass doors and cabinets, glossy paper and shiny desk or table tops should be minimized. Whenever possible. non-glossy paper should be used. Covering a desk or table top with dark, non glossy cloth or construction paper can also reduce reflected glare. When using some computers, glare can also be reduced by changing the polarity which means reversing the image so that the print is white and the background is dark. Scatter glare occurs when light bounces off particles in the eye or particles such as dust, fog, or smoke in the air. Sometimes, cataract surgery may be required to reduce scatter that occurs because of lens opacity. Outdoors, glare can be controlled by having youngsters wear caps, hats, visors, absorptive lenses, and/or shields that keep excess light from entering beyond the edges of spectacles.
The placement of light sources in relationship to youngsters is important. In classrooms, teachers should seat the child so that he or she does not have to look into direct light. Glare, as well as the likelihood of tired eyes, are all increased by looking directly into light. Teachers should also be careful not to stand in front of windows when talking to children who have greater than normal light sensitivity. Albinism (loss or absence of ocular and skin pigment), achromatopsia (absence of color-vision sensitive cells in the retina), or aniridia the absence of an iris or pupil so that light entering the eye cannot be adjusted) are all causes of light sensitivity in children. Shades or blinds which can be used to control natural light entering the classroom or home provide a significant means for increasing comfort and effective use of vision.
Children ought to be allowed to define the amount of light that gives them maximum visual comfort and function. Focal illumination, under the child's control, such as a table lamp or spotlight, is recommended. The general rule, whenever possible, is to try for uniform quality of lighting and elimination of the causes of glare and scatter. In this way, you can help a child with impaired vision maximize the use of his or her remaining vision.
Norman B. Medow, MD, FACS, is Director of Pediatric Ophthalmology, Manhattan Eye, Ear and Throat Hospital, New York, NY.
Source: The Lighthouse Inc.'s EnVision newsletter (Spring 1993 issue)
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