Rather worryingly I noted a post on the C+ forum by one poster who claimed he never sees a GP (does not trust them!) nor does he see am optician "because they are out to fleece him!"
Observation skills will never improve if you have an uncorrected eyesight defect. Most people pass the basic requirements on the day of the L-test and rarely get their eyes tested until they expereince some difficulties in reading or watching telly.
Thus it remains for individuals to be responsible about eyesight checks. I'd recommend a check every 18 months or so. After (gulp) age 40 --it's all downhill....
This is the age where eyesight starts to deteriorate - and if you drive with a uncorrected eyesight defect - this is an offence and we will prosecute for this. No discretion whatsover! We can require you to take an eyesight test at any time in good daylight - and have been known to do so!