The relationship between lighting and vision

The relationship between lighting and vision
Visible light passes through the cornea of the human eye, forms an image on the retina, and then transmits signals through the optic nerve to produce vision. In addition to producing vision, light can also affect people's circadian rhythms, such as affecting the secretion of melatonin, thereby affecting sleep and so on. From the perspective of the path of light, if the light affects the cornea, the retina, the brightness of the light, etc. will affect vision. A lot of invisible light is blocked outside the cornea, but blue light can penetrate the cornea and reach the retina. If there is too much blue light, it will cause eye damage due to too much blue light. 80% of the information obtained by people is obtained through vision. Human eyes and brain cooperate to form human vision. What the human eye can pass is the visible light of 380nm-780nm. These visible lights can adjust the amount of light entering through the pupil. The light amount and color image information pass through the complex visual system and finally make people see. The sensitivity of the relevant visual cells of the human eye is different under different illumination conditions. For example, in a darker environment, the rod cells play a major role. These different situations form photopic vision, scotopic vision, and intermediate vision. For example, on a moonlit night, scotopic vision may be the main function of the human eye, so that people can roughly see objects. Whether in scotopic vision or photopic vision, the human eye is the most sensitive to green light, so in general, the human eye is the weakest in green light vision. The sensitivity to red light, etc. is weak. Although the human eye has photopic and dark vision, there is still an adaptation time in places where the corresponding light and shade are different. The human eye’s adaptation time to bright environments is very fast, reaching the level of seconds or even milliseconds, and it can be completely completed in about 2 minutes. adapt. It takes longer to adapt to a dark environment, maybe 20 minutes or 1 hour. The specific adaptation time needs to be determined according to the degree of light and dark changes. We also have this kind of experience in our lives. For example, when some people ride in a car, from the tunnel to the exit of the tunnel, the eyes will have an adaptation process. Although it is very fast, there is a process to fully adapt to seeing and distinguishing objects. Knowledge can also remind drivers to pay attention when driving. We usually feel acclimated to bright places faster. But adapting to dark places is relatively slow. For example, when we enter a movie theater, it feels completely dark when we first enter. How can we see clearly? But after a period of time, our eyes completely adapt to the dark environment, and our dark vision is fully mobilized. At that time, the human eye can roughly see clearly, which is completely different from the feeling of darkness in front of the cinema just now. But when leaving the movie theater, the human eye will feel that it is too bright at the beginning when it changes from scotopic vision to photopic vision, but it adapts very quickly, and it will completely adapt in a short time. As the elderly grow older, their body functions degrade, including the lens of the eye begins to harden, the transparency becomes poor, the ability to adapt to light and dark environments decreases, and the ability to control light weakens, so more attention should be paid to glare, stroboscopic and other adverse effects In addition, you need to pay more attention when entering and exiting places with strong contrast between light and dark environments. For example, you need to be very careful when entering and exiting places with particularly strong light contrast such as movie theaters. In daily life, especially at night, it is necessary to create a better lighting environment to help see objects clearly. Therefore, there will be special lighting design for the elderly. For example, in the elderly’s room, it is necessary to increase the illuminance and color temperature, considerate foot lamp design, and it is best to have lighting fixtures that can guide the elderly to wake up at night, etc.