For some reason, I came out of the hat to have a medical before DVLA would renew my 3 year licence.
The medical was difficult to get a date for as a 20 minute appointment with your doctor is required and these, apparently are like hens teeth. That said, I managed to get one just within the 6 week deadline. This, however, became a victim of the Covid lockdown when all routing appointments at our surgery were cancelled until further notice.
DVLA's letter gave advice to get in touch with them should this happen. Getting in touch with the DVLA is not the easiest thing to do. The number on the letter to me to a line for collecting payments, whilst all of the other numbers given had a message saying call back due to the current volume of calls being received. I went back to the payment line, which was still being answered and the very nice operator put me through to the relevant department.
The upshot is, that a note has been added to the case file recording the cancellation of the medical. They confirmed that I can carry on driving after my licence renewal date and even sent an email confirming the relevant section of the road traffic act to quote if stopped.
I'd get in touch to ensure that your licence isn't automatically revoked due to this as it may happen automatically if no confirmation of eye test is received.