A face shield that does not fit tightly to the face can cause changes in the surface of the cornea or conjunctivitis, which can reduce visual acuity. The chief physician of the city polyclinic 46 Denis Serov told the Moscow City News Agency about this.
“A recent study by Danish scientists suggests that long-term use of the mask can lead to the development of dry eye syndrome. These are serious changes on the surface of the cornea and conjunctiva, which develop due to the lack or insufficient moisture in the tear fluid. This condition, as a rule, is felt in the form of discomfort and can often lead to a decrease in visual acuity and even injury to the cornea. Scientists have found: if you wear a mask for a long time, the air that a person exhales constantly circulates up and down. But if the mask is loose on the face, most of the air comes out from the top. Thus, its flow near the eyes increases - the tear film evaporates faster,”Serov said.
As he noted, in order to avoid visual impairment when wearing a protective mask, it is necessary to change the mask every two to three hours and make sure that it fits snugly to the face.
“When using disposable medical masks, you need to remember that the optimal time to use them is two to three hours. If you are walking alone in the park and there are no other people nearby, then the mask in this case becomes irrelevant. In case of dry eye, you can use moisturizing drops based on natural tears. In case of progressive deterioration of vision, you should immediately contact a specialist,”Denis Serov emphasized.