Your description is inadequate to really judge. A picture would be very helpful. My educated guess would be that you have Pear Scab. Are the dimples black? If so, it's probably scab, which can be quite serious, but is usually light enough to ignore, except on very susceptible cultivars. It's a fungal growth and poses no real problem to you or the tree, as long as it's not severe enough to shrink and distort your pears.