Apple watch

Unless you are looking at used watches, Apple sells 41mm 45mm and 49mm (the newest Apple Watch Ultra) sized watches.

If you have vision issues, the larger the face, the easier it will be for you to read Apple Watch. Apple Watch Ultra is the newest, largest face and most expensive of the Apple Watches (unless you want the limited edition, more expensive Hermes Apple Watch).

Perhaps comparing models will help you --> Apple Watch - Compare Models - Apple

Dodiemarr wrote:

Do the 38mm 40mm 44mm etc relate to the size of the case/face? Or simply the wrist/strap size?

Case size. Please refer to Watch - Apple.

You're welcome. I just moved up to the Apple Watch Ultra from a 45mm Series 7. Trust me, the larger screen is amazing. The price is high though, so not a purchase taken lightly.