I see no AI breakthroughs. I see image processing.
60 years later, we have finally made general purpose learning algorithms, vaguely inspired by the brain, which are just powerful enough to do it. And because they are general purpose, they can also do many other things as well. Everything from speech recognition, to translating sentences, or even controlling robots. Image recognition is just one of many benchmarks that can be used to measure progress.
A good introduction to how the visual cortex works can be found in Eye, Brain, And Vision: http://hubel.med.harvard.edu/book/bcontex.htm
[1] Sorry, don't have a cite, but there are a lot of results on Google talking about it: https://archive.is/iDE27