Adding Stick-On Lenses to Cycling Sunglasses
These lenses solve a problem for people who need reading glasses while they're out using a cycling computer. My eyesight is no longer 20/20, and this quick video shows you how to use these stick-on lenses on your sunglasses.
They turn your regular sunglasses into inexpensive bi-focal sunglasses.
I bought these at Amazon: https://www.amazon.co.uk/dp/B0C55FZDL4
But check out Aliexpress for cheaper - sometime much cheaper - options.
Note that I paid for these myself.