From the "DAME Newsletter - September 2016" here:
https://www.casa.gov.au/licences-and...september-2016
Wear glasses when they fly? Remind them to bring their spare pair
If an applicant wears contact lenses or glasses when they fly, they are required to bring their spare pair of glasses with them to their aviation medical examination.
To avoid any unnecessary delay in the medical certification process, ask your receptionists to remind applicants to bring their spare glasses when booking aviation medicals.
Why are applicants "required to bring" a spare pair to the medical examination? Because someone in AVMED woke up one morning and decided it was a bright idea to help save the world, that's why.
AVMED just makes this **** up as they go along.