Your pear tree may have some leaf spot disease, but there was also some caterpillar damage to the foliage several weeks ago.  While a probable leaf roller caterpillar was on the foliage, the leaf came in contact with the developing fruit and the caterpillar simply took advantage of the proximity and fed on the skin of the pear.  What you see now is 'scar tissue', formed by the fruit to seal off the wound and 'heal' itself.
The damage is superficial and the fruit is still edible. 
If you choose to treat these insects next year, monitor the tree for their presence and spray the tree with Bt 'Kurstaki'. 
The leaf spot diseases require a preventative schedule of fungicidal sprays beginning at bud break in the spring and continuing every 10-14 days throughout the growing season (until 2 weeks before harvest).
LS