There are different eye sight standards for a hgv medical and are dependent on when you gained your HGV entitlement, I wouldn’t pass the current standard but can pass the one that can be used under grandfather rights without having to wear glasses to drive.
Visual acuity
Exception 1
A driver must have been awarded a Group 2 bus and lorry licence before 1 March 1992, and be able to complete a satisfactory certificate of experience, to be eligible.
If the licence was awarded between 2 March 1992 and 31 December 1996, visual acuity with corrective lenses if needed must be at least 6/9 in the better eye and at least 6/12 in the other eye; uncorrected visual acuity may be worse than 3/60 in one eye only.