You should know that the rheum or sleep we usually all have in our eyes every morning is a natural response of the body, as not blinking during the night means we can not eliminate some substances. What you should bear in mind is that it is essential that when you wake up you clean the eyes thoroughly and correctly as they are a part of the body that is very sensitive to possible infections. Perhaps this has happened to you. If you notice that large amounts of crust are forming, or if there is pus in it, this may be a symptom of a dry eye or other more serious ocular infections such as conjunctivitis or keratitis. In this case, you will need to take greater care and clean your eyes more.
Also, if you normally wear eye makeup you should take notice of this advice. When you take your makeup off, clean the whole eye area thoroughly to prevent discomfort or possible infections.
However, perhaps you are concerned because the person suffering from sleep in the eyes is a small child, or even a baby. Those are perhaps the people who are most affected by rheum, and an excessive amount can make it very difficult for them to open their eyes when they wake up. In these cases, ocular hygiene should be impeccable and, as well as using clean water, it may be advisable to use an additional method of hygiene.