Can deer not see well? Are they slow to process what they see?

For half of my last few rides, I've been blessed or cursed with deer in the road ahead of me.

I make noise to try to get them to move on.

The problem: They stand there and stare at me...do they see me from 75 feet away? 50 feet? 25 feet?

Unfortunately, they're often standing in the other lane...and I'm afraid a car will crest a hill and hit the deer right in front of me hurting the deer, the driver, or me

Are there special techniques to avoiding this?