Dr. Ripudaman Singh asked:


ter and Class Room Environment



Lighting is one of the most overlooked and underemphasized components of our indoor environment. Whether working at the computer or in a warehouse arena, our field of vision needs to be free of reflections and sources of glare. Our lighting needs to prevent problems, not cause them. Lighting is effective when it allows us to see the details of a given task easily and accurately. Comfort in lighting is a very individual concern, and must be addressed on a one-to-one level; no one lighting pattern will work for every working situation. Those in charge of classroom lighting need to learn what is available to help them make the right choices for the students. As lighting and vision are interdependent factors, both must be considered when designing a classroom environment for maximum efficiency. It is imperative that we increase our awareness and knowledge of how lighting affects schoolwork.

Poor lighting can be a source of visual headaches, which most often occur toward the front of the head (there are a few exceptions to this), or toward the middle or end of the day. They do not appear upon awakening, often occur in a different pattern on weekends than during the week, and can occur on one side of the head more than the other. Other symptoms—such as eyestrain, tired eyes, double vision, and red or dry eyes—are more general.

An important factor that affects our ability to see well is the quality of light. Good-quality light creates good visibility and visual comfort, and involves brightness, contrast, as well as the quantity and the color of light. Contrast between a task object and its immediate background must be sufficient to enable the student to clearly view the task. The contrast ratios involved in classroom lighting should be considered so rooms can be set up to maximize productivity without increasing eyestrain.

Too much or too little light can inhibit the student’s ability to see the task effectively. Comfortable light levels will vary with the individual as well as the task. The more rapid, repetitive, and lengthy the task, the more important it is to have enough light. With these types of tasks, the eye is more vulnerable to fatigue and the student or worker to declined productivity. Children often use computers in a home or classroom with less than optimum lighting. The lighting level for the proper use of a computer is about half as bright as that normally found in a classroom. Increased light levels can contribute to excessive glare and problems associated with adjusting the eyes to different levels of light.

Different colors of light will create different moods or atmospheres that will affect a student’s sense of well-being and level of productivity. Color-corrected lights come closest to nature’s light, imitating the color rendition of the noonday sun and adding a whole new sense of well-being to the classroom environment. This can be achieved by altering the lighting sources, or installing a special filter that can be placed between the lens and lamp of a fixture, or fit as a sleeve over each lamp. People designing classrooms, especially for computer use, must understand a number of important factors that should affect the choice of lamps and/or lighting products.

Classroom lighting that was acceptable in the past is no longer acceptable today. The average ambient light levels in most classrooms are too high, too inefficient, and too costly. The trend now calls for reduced ambient lighting, supplemented by adjustable task lighting. Recommended light levels for today’s computerized classroom is 40-50 foot-candles for ambient light, compared to 100 foot-candles or more in previous noncomputerized offices. Many classrooms have no task lighting, yet readily available task lighting systems are advanced, versatile, and can illuminate work surfaces and tasks without creating veiling reflections or glare on VDT screens or work surfaces.

Lighting a classroom for maximum efficiency is a nice concept. In the real world of budgets and bottom-lines, however, cost effectiveness is also a major consideration. The cost of energy, of new lighting fixtures, of retrofitting, of remodeling, and more are all significant considerations that must be balanced to achieve the most for the money spent. It might help to know that approximately 86% of the cost of lighting covers energy consumption, while only 3% involves the price of the lamp. Therefore, purchasing cheaper lamps does not necessarily lead to cost savings; these are achieved by purchasing lamps that consume power more efficiently.

The following recommendations will lead to good classroom lighting decisions:

1) Learning to observe the types of lighting available to a student and to develop ongoing awareness of how they may or may not be working;

2) Identifying risk factors, such as glare and reflections, and the many options for correcting these factors;

3) Developing solutions that involve teacher responsibility, administrative cooperation and caring, and realistic cost-effective improvements.

 



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