Is studying at night with only a desk lamp and no overhead light harmful to the eyes?

Generally, studying at night with only a desk lamp and no overhead lighting can be harmful to the eyes. The specific reasons are as follows:

Indoor lighting is relatively dim at night. If only a desk lamp is used during study without turning on the main light, the limited illumination range of the desk lamp often results in insufficient overall room lighting. Studying under such conditions—with a bright spot surrounded by darkness—causes the eyes to constantly adjust between light and dark environments, which may lead to eye strain. Additionally, if the desk lamp is placed too close, it may excessively stimulate the eyes. Over time, this may negatively affect vision and increase the risk of developing myopia.

It is recommended to maintain good habits: ensure appropriate indoor lighting brightness while studying, keep a proper distance from reading materials, and avoid eye discomfort.