Illuminance is closely related to people's lives. Adequate lighting can prevent people from having accidents. On the contrary, too dim light will cause people's fatigue, which is far greater than the eyes themselves. Therefore, uncomfortable or poor lighting conditions are one of the main causes of accidents and fatigue. Existing statistics show that about 30% of all occupational accidents are directly or indirectly caused by insufficient light. The lighting requirements of the stadium (gymnasium) are very strict. Too strong or too dim lighting will affect the result of the game.

Then, what are the sanitary requirements for the illumination in the room where people live? Illuminance is a very important index in hygiene. Light refers to electromagnetic radiation that can make people's eyes feel bright, and the perception that light can produce when it enters the eyes is called vision. The light people see refers to visible light, and its wavelength range is between 380 and 760 nm (nanometer).

Daylighting can be divided into natural lighting and artificial light source. Natural lighting refers to the indoor and regional natural illumination, including direct scattered sunlight and reflected light from surrounding objects, which is often expressed by lighting coefficient and natural illumination. Daylighting coefficient refers to the ratio of the effective area of daylighting opening to the indoor floor area. The daylighting coefficient of a general house is between 1/5 and1/5, and the living area ratio is between 1/8 and1/0 (window area/indoor building area). The natural illuminance coefficient is used to evaluate the illuminance level of natural light. It reflects the relationship between indoor and outdoor lighting. It also reflects the local light climate (the sum of natural light energy and sunlight illumination index of the climate).

In order to ensure people's living under suitable lighting, China has formulated the hygienic standard for indoor lighting (including public places). For example, the lighting hygiene standard of public places in shopping malls (shops) is ≥100lx; Hygienic standard for table lighting in libraries, museums, art galleries and exhibition halls ≥100lx; Hygienic standard of public bathroom illumination ≥ 50lx; Bathroom (shower, swimming pool and bathtub) ≥30Lx, sauna ≥30Lx. Foreign standards on indoor lighting, such as several rated light intensities recommended by Germany, include 300Lx for office in clerical work area and 750Lx for typing and drawing; In the factory, the illuminance requirement for visual work on the production line is1000lx; ; Hotels and public * * * rooms are all 200Lx；; Reception point and cash register 200Lx；; Shop window1500 ~ 2000 LX; Hospital ward 150 ~ 200 LX, emergency area of 500 LX；; ; Schools and classrooms are 400 ~ 700 LX, canteens and indoor gymnasiums are 300Lx.

As for the measurement method of illuminance, it is generally measured by illuminance meter. Illuminator can measure the intensity of different wavelengths (such as visible light and ultraviolet light), and can provide accurate measurement results for people.

In a word, lighting is of great sanitary significance to human health, especially to eye care.