Good Light for the Golden Years

By Dr. med. Dieter Brodehl, Ophthalmologist, Darmstadt, Germany

Everyone knows mothers old saying: "Turn the light on; otherwise you spoil your eyes!" We learned with this ancient wisdom to see worse in low light, the idea that an insufficient lighting could draw an organic damage to itself. Although this wisdom is not quiet correct, it indicates that there is a close connection between light, eyesight and wellbeing.

Especially with increasing age, we become aware of the importance of "good light" at home or at our workplace. Because two decisive self-regulating mechanisms of seeing, the close-up reaction (accommodation) and the adjustment to brightness (adaptation), diminish in the course of life.
When accommodate, the eye can image sharp objects on the retina at different distances by varying the thickness of the lens. Since babyhood, this lens becomes harder and thus more inelastic, so that with the age of 40 to 45 the emmetropic eye cannot see sharp closely any more. It needs reading glasses.
In addition, the eye becomes more glare-sensitive. Light densities in the visual range, as in the extreme example when driving out of a tunnel, decreases in the course of life. In addition, the pupil becomes narrower with increasing age and therefore less light enters the eye.

Reading in Poor Lighting

If one reads only in bad lighting, the pupil would have to open further, but they cannot do so because of their age-related characteristics.

How can we counter these natural disadvantages with an improvement in the environmental conditions? First of all, the lighting intensity is an important parameter in addition to an optimal compensation of the refraction errors (possibly spectacles), with which we can counter the diminution of accommodation and adaptation.

The example of the simple photo camera is familiar: in the sun we set the diaphragm very narrow and the image becomes sharp from one meter to infinity. Precisely this phenomenon of sharpening depth is used unconsciously when we use a brighter light bulb in our reading lamp. The pupil becomes narrower, the sharpening depth becomes larger.

When Reflexes Glare

The most common causes of complaints about lighting systems are caused by direct and indirect (reflex) glare. These symptoms are increasing with age-related lens character. How can you tell if there is glare?

If you feel that you are blinded when looking straight ahead, you can simply cover the light source or the reflective surface with your hand or a book. If now the impression is that the view is more pleasant, it is either direct or reflected glare. From shielding to the replacing the luminaire, there are numerous ways of solving this problem: a bright illumination is stimulating and invigorating.
But too much brightness (luminance) can lead to interference. A too bright light produces over-excitation and premature fatigue.

Using Light Right

Therefore it is important to deal with light properly. Any improvement in the field of lighting may saves us concentration and brings us hence quality of life. The light intensity also influences the reactivity and performance.

A rough guide for good lighting at home can be: The light spectrum of the lamp should be similar to the sunlight, i.e. warm-white. A brightness that corresponds to a 60 to 100 watt incandescent lamp should be present at the desk. The double values apply for fine work. In this case, the limits of pure incandescent bulbs illumination become very clear. Because of the temperature development, fluorescent bulbs often have to be the replacement. Qualified retailers offer a wide range of compact fluorescent bulbs.

Instead, "Make yourself light, or you'll be ruining your eyes", so it should be: "Get enough and good light and save your concentration and life energy."