First of all, the brightness should be appropriate: if the brightness is too low, the light on the book is dark, it is not easy to see the writing, which will cause visual fatigue, and it will cause myopia after a long time. If the brightness is too high, too strong light will be reflected into our eyes through the white paper surface, producing glare, causing the pupils to continue to shrink, which may cause eye pain and headaches. In general, a soft and uniform white lamp brightness is most suitable.
Secondly, the position of the desk lamp also has a great influence on vision: because most people write with their right hand, the desk lamp should be placed in front of the left side of the body, and when writing, it will not form a shadow on the paper due to the hand covering, and shine on the paper The light will not be reflected into our eyes and cause glare.
Finally, the height of the table lamp is also very important: usually, when the eyes are 30 cm away from the book, you can see the writing clearly, and you will not be excessively fatigued. Based on this, the height of the table lamp is more suitable to be 40-50 cm from the writing, so as to ensure sufficient Reading lighting, the surrounding environment also has a certain brightness.
If the desk lamp is too high, the light will directly hit our eyes and cause glare; at the same time, the close-range strong light will also cause light retention on the retina, which will tighten the eye muscles and accelerate the decline of vision.
If the table lamp is too low, it will cause the light to shine in a too small range, and the surroundings will be dark. Losing the reference object for long-distance vision will cause the eye adjustment systems to be in a tightly compressed state of looking only at the near position, which is easy to fatigue the eyes and accumulate quickly, resulting in “light source myopia”.
