Williams Pear - Manky Leaves?

Hopefully it is a mite. a book I have mentions it as the Pear leaf blister mite but that it isn't a serious pest recommending removing badly affected leaves. The shoot look healthy enough so likely not fireblight.

Edit: I noticed some ants on a pear tree so had a closer look for the aphids they were likely going to farm. Squished all I could see.