Care for the elderly and children with eye health lighting design should be "people-oriented"

Regarding light and health, although the professional span involved is very wide, many institutions and enterprises abroad have done quite a lot of research. At present, more and more research teams in China are beginning to get involved in this field, such as the team of Mr. Hao Luosi from Tongji University, but this is a scientific and rigorous research work. It is estimated that it will take time to see the real results. .

It has been agreed that the demand for light, the need for lighting design, and the sensitivity to brightness and glare to older people and infants and young children is different from that of adults (commonly referred to as "we"). The world that the author of this article sees from the eyes of the elderly is different from “we”, reminding the industry (whether standard makers or ordinary practitioners) to notice those “we” may or have been neglected (only It is because they have insufficient voice and cannot make their voices. In the face of light, they should be treated equally.

The so-called equality means that their needs should be fully recognized and considered in the same way as "ours." In fact, what it asks for is not treated the same, but treated differently. So, as the authors say, we must keep in mind that it is easier to design with reference to standards, but “people-oriented” is more important.

I am a normal person, I can't hope that you will be worthy of your attention in the crowd.

- "Inspiration for Love"

We live in the same world as our parents, but few realize that the same scene, what parents see is different from what we see.

The human visual system consists of three parts: the eye, collecting external information through reflected light; the optical path, transforming the visual information collected by the eye into a signal; the visual cortex in the brain, saving and translating information, thus allowing us to truly "see" To.

â–² Human eye structure chart

As we age, our eyes and brain become more or less physiologically and neurodegeneratively:

★ The lens of the human eye may harden and the ciliary muscles become weak, causing the focus of the human eye to weaken. This can lead to difficulties in seeing small words or looking at close objects, commonly known as presbyopia. Generally this change starts around the age of 40 and can be partially compensated by wearing appropriate glasses.

★ Our pupils will gradually shrink, and the ability to adjust the pupil size with light intensity will also become smaller, which means that less light will enter the eyes, causing people to see in dim light. With age, the maximum diameter that the pupil can open may be only 1/4 of that of a young person, which means that the same amount of light that an 80-year-old man can get on the retina may be only 20 years old. It can get 1/6 of the amount of light, or even less.

★ The lens in the human eye gradually changes from light yellow to dark brown. The pale yellow lens filters out most of the UV rays, including UV A and UV B, so that they do not reach the retina, protecting our eyes from UV light. However, as the color of the lens becomes darker, the short-wavelength light such as dark blue or purple is filtered out while filtering out the ultraviolet light. This will cause the colors in the eyes of the elderly to be less vivid and to make it more difficult to distinguish between blue and green.

★ Similarly, as the age increases, the human lens will gradually become cloudy, which will cause more light to be scattered, resulting in poorer contrast of light reaching the retina, and more ugly and clear edges and details. Under strong light, objects in the field of view become larger and more blurred. Adding the above two further reduces the image quality on the retina.

★ In addition, as the age increases and the human eye ages, more clumps will appear in the eye (the vitreous part). These clumps will reveal one or more dark areas in the field of view, which will cause serious light scattering in the eye. This means that less light is available on the retina, and ultimately a stronger, brighter light is needed to see.

★ Finally, as the eyes age, the adaptation time from bright to dark is significantly longer. Usually 20-year-olds need 30 minutes to adjust the vision from a full-light environment to a dark environment, but for older people, this time may take 45 minutes or longer.

â–² Human eye transmittance decreases with age