From the perspective of geomantic omen, is it ok to sleep with the light on at night?

Not so good. From the perspective of geomantic omen, night is the time when the sun be the spirit converges, avoiding the loss of the sun be the spirit. Moreover, at night, the essence of the sun begins to condense, and the essence of the sun in the human body is hidden under the shade to protect the yang with the yin, thus achieving a kind of recuperation. If you turn on the light, it will increase the disturbance of the spirit of the sun, making people restless and easy to get lost. At the same time, the quality of such sleep will also decline, because the body has not got a good rest. Of course, it doesn't have to be completely dark at night. You can have a nightlight.