How does one "buy dedicated lenses for that distance"? The distance between my eyeballs and my screen is 28 inches, but I do not know how to translate this into what to buy.
your prescription - (100 / desired distance in cm).
As a matter of fact I'm using glasses I bought this way right now. I actually find these even more comfortable than my full degree glasses for all-day use too, in terms of eye strain.
I feel it's ridiculous that the medical industry thinks I need to wear glasses that are powerful enough to focus an image of a mountain 100 kms away all day, when my average focus distance throughout the day is probably less than one meter.
These reduced degree glasses are called differentials. If you want to go into the rabbit hole of fixing your myopia, start here: https://www.youtube.com/watch?v=XPIGDSY_xBs
Disclaimer: When driving, you have to obviously wear your full prescription glasses.
That being said I'm even less sure how to calculate it now.
My understanding is that eye strain is either caused by unbalanced lightning (e.g. bright screen in dark room), or focusing on close distance for too long without giving the muscles a break by focusing further away. The well known 20-20-20 rule tries to establish that. As a practical advice, you may try adding some small walks, getting some fresh air for a few minutes, or even looking out of the window for a few minutes throughout the day.
FYI, iPhones have a feature to tell you to use your phone further away when you use it glued to your face. If you have myopia, it should go without saying that you should never use your phone with your glasses.
Apple could detect that the user is wearing glasses. During FaceID registration, the phone could ask whether the glasses are for distance (myopia) or closeup/reading. If distance, the phone could offer to remind the user to remove their glasses after using the phone for more than X minutes.
Ask optician to customize the intermediate/computer glasses for your work posture, e.g. looking straight ahead (monitor) or down (laptop).
For those with more time than money, learn from opticians at https://www.optiboard.com/forums/ before ordering online.
You can also order 0.75 diopter glasses on Amazon that work real well.