Plus they make rear view mirror sunglasses that might come in handy...
These old tickers don’t appreciate surprises like they used to.
;-)
I don’t get that startle problem as much, now that I am retired and don’t get engrossed in an engineering problem or computer spreadsheet.
Back when I was working, if I was focused on something, the rest of the environs went away, and so if someone came up behind me, I would startle when they spoke to me.
It wasn’t so bad if they came to my side or in front (we had those low wall offices) so I saw them coming first, but with the old high wall offices, the doorway was to my back and I wasn’t able to get a visual alert.
Mirrors didn’t help though.