• Assessment of visual acuity at routine revalidation medical assessments.

    For regular contact lens wearers with a VDL limitation on their medical certificate, it is not necessary to measure (unaided) vision (right eye (R), left eye (L), both eyes (B)), visual acuities (VAs) with specs (R,L,B) and VAs with contact lenses (R,L,B) at every revalidation medical assessment.

    A contact lens wearer should have their VAs checked with their contact lenses in-situ every other medical and have their (unaided) visions and VAs with spectacles checked at medicals in between, thus alternating between glasses and contact lenses at each medical.

    There are a number of reasons for doing this.  Firstly contact lens wearers will have more regular checks (usually 6 monthly) at their local optometrists compared to purely spectacle wearers (yearly or 2 yearly) so it is very unlikely that the lens prescription is incorrect.  Secondly, if the (unaided) visual acuities are checked and the pilot is then asked to insert their lenses, checking the VAs immediately does not give a true representation of the performance of the lens once settled.  This can take 5-10 minutes in some cases and VA will improve in that time.  Thirdly, a contact lens wearer is more likely to have poorer unaided visual acuities, as they are more reliant on using correction and therefore have a greater visual benefit from wearing contact lenses. Finally, for both the pilot and examiner, this process will save time.