UK statistics here:
https://www.gov.uk/government/statistics/reported-road-casua...
The issue is that the rate of accidents rapidly increases after 70 and the easiest detectable indicator is deteriorating eyesight.
I think testing eyesight is important. In fact you need to make a declaration about your eyesight when you first get a license and when you renew after 70. There is no real enforcement of the former either (they just ask you to read a number plate at a distance IIRC).