Kindly squeez, out the white substance under that closed eye and swap with 10% iodine. You have a case of wet fowl pox. Very fastidiuos indeed to manage once in. Vaccination and all in all out is the only solution to this. If the bird is of less value then you can put down to prevent the risk of spreeding it to others. Remember the bird dies of starvation because the eyes are closed hence suportive therapy(ensuring that eyes are open) giving multivitamin should come handy.