I now know it was gradual - at 40 I was laying with my head inside a cabinet and was going to tighten a screw. I saw that it was defective because there were no slots for the Philips head. When pulled out and looked at it, the slots were there. After puzzling for a minute, I realized my close up vision must be going. Then at 45, I would look at something like a distant vulture against the blue sky and I would see it double. That is when I thought I had a tumor. The contacts cleared that up - so moral of the story - before you sell the farm, see an Opthomologist....
