She explains that the eyes are a part of the brain that is shifted to the periphery, and for normal nervous system function, at least seven to nine hours of sleep per day is necessary. Insufficient sleep leads to elevated levels of stress hormones, which can lead to negative consequences for eye health. For example, increased intraocular pressure, risk of developing glaucoma, deterioration of visual quality, and other problems. Lack of sleep can also be the cause of various diseases, such as diabetes, infections, and arterial pressure disorders. Therefore, it is very important to sleep for at least seven to nine hours per day to maintain eye health and the nervous system as a whole.