It is very easy to touch your face without noticing.
If your fingers have viruses on them and then you touch your eyes, nose or mouth you are likely to infect yourself. Our eyes have tear drains that flow into the nose and so can pass germs down into it.
This is why it is good to wash/sanitise your hands as often as possible as you may touch your face at any time without noticing.
Washing your hands with soap stops viruses being passed from your hands to your eyes, nose and mouth. Water alone does not kill germs.
If soap and water aren’t available, sanitising with using hand gel is a good idea.
Washing/sanitising your hands is an important way to stop the spread of illnesses.