Lorry and bus drivers
You must have a visual acuity at least 0.8 (6/7.5) measured on the Snellen scale in your best eye and at least 0.1 (6/60) on the Snellen scale in the other eye.
You can reach this standard using glasses with a corrective power not more than (+) 8 dioptres, or with contact lenses. There’s no specific limit for the corrective power of contact lenses.
You must have a horizontal visual field of at least 160 degrees, the extension should be at least 70 degrees left and right and 30 degrees up and down. No defects should be present within a radius of the central 30 degrees.
Taken from. Gov website.
It states you must be able to reach the required eye test with no more than 8 dioptres with glasses then goes on to say there is no specific limit for contact lenses as I read it.
So I would say with glasses above 8 dioptres then no you wouldn’t meet the requirements, but I read it as with contact lenses then you should.
That’s how I read it at least.
Not sure what real difference there is whether wearing glasses or contact lenses though so why there seem to be a difference I don’t know.