Photo of the orange marks might help.
Could be rust. In which case it would not normally affect the flowers.

It could be pear leaf gall Dave. No real harm to the tree but annoying to look at. Dispose of the leaf by burning if possible. Not a good year for my pears either. 3 out of five have a reasonable crop. One has speckled leaves, one no pears at all, but has sent out a foot of new growth all over, but no fruit. Prepare to be teased and frustrated if you cultivate apples and pears!!!!!