First, sitting and sleeping: It is often seen that someone is sitting and taking a nap instead of taking a nap, which is not conducive to eliminating fatigue. When the human body is sleeping, the muscles of the whole body relax and the blood circulation slows down. If you fall asleep sitting down, the blood supply to the brain will be reduced due to posture, and a series of symptoms of cerebral ischemia and hypoxia such as dizziness, dizziness and fatigue will easily appear after waking up.
Second, fall asleep on the table: Some people like to sleep on the table with their hands as pillows. Do you know that this will increase intraocular pressure and easily induce eye diseases over time? Some people will have symptoms such as temporary blurred vision and "blackening" after a nap, which is caused by the deformation of cornea, lens and curvature caused by the change of eyeball pressure. Congenital glaucoma is also caused by long-term high intraocular pressure, which makes the eyeball swell and the axial length lengthen, thus forming high myopia. Therefore, long-term nap at the desk will lead to high intraocular pressure and impaired vision.
Third, the nap time is too long: experts believe that the best nap time is during the natural decline of human alertness (12- 13). In the meantime, an hour's nap will refresh you. Because people's cerebral cortex inhibition is strengthened during sleep, there is a period of excitement inhibition in a certain period of time. If the sleep time is too long during the day, the brain inhibition will gradually deepen, and the human body will feel extremely uncomfortable, more sleepy, top-heavy, weak, confused and unresponsive. So the nap time should not be too long.