Bees have Hairy Eyeballs

I suffered withdrawal symptoms today and was compelled to visit two apiaries in order to get a “fix” and see some hives. All were okay but it was early in the day and with a frost there was no activity. Still it seemed to help!
I went to a local meeting tonight and enjoyed the talk given by Neil Harrison which gave comparisons and differences of honey bees and wasps. I had heard it before (a good few years ago!) but I was able to understand it better on this occaision. The title and closing line was that Bees have hairy eyeballs, backed up with a comparison slide of the corneas of the honey bee and wasp. However the reason for this was unknown. Anybody know?