This looks like a leaf spot called frog eye or black rot. This is a late summer disease http://extension.umd.edu/growit/diseases-apples-and-pears
Some varieties may be more susceptible than others.
We do not know how you manage your trees. If only on the leaves, this may not be a factor. However, if this affects the fruit, you will have to adhere to a spray schedule. Take a look at the schedule for VA Tech http://extension.umd.edu/growit/home-fruit-preventative-spray-schedule-and-management-common-problem...