The practical details of implementing this are important - is the eye test done at an ordinary optician/optometrist's shop? How are the results going to be submitted to DVLA, etc.? What protections will be in place to prevent people from shopping around for a dodgy optician (as people often do with cars and MOTs)?
I think this is a reasonable and practical step in the right direction. I accept that given the shortage of driving examiners it would be impossible to require re-testing of existing drivers in the foreseeable future, but as the article says, people already get eye tests frequently and often for free, so this is something that can be done without too much additional infrastructure.
A personal anecdote: my grandfather is in his 90s and is not at all fit to drive due to cataracts and various other issues, but he still does "short journeys" because it's convenient and he feels that it's necessary. The UK has plenty of public transport options and places where people can live with amenities close by (though this is not at all universal). Most British towns and cities are very different from their US counterparts in this respect. My grandfather moved house relatively recently --in full knowledge that the house he chose would benefit from car ownership, and in full knowledge about his age. The only thing that will stop him and others like him from putting people in danger is taking away his licence. He has been told by doctors, opticians and family members that he's not safe to drive, but in the absence of any enforcement he persists. I hope that this policy comes in before he or someone else gets hurt.