Local Hardware (Home Depot / Lowes / Ace etc.) / Craft stores (JoAnn's, Michael's, Hobby Lobby) might have something like these to try out. Office supply stores might have some of them also. The stand magnifier uses a Fresnel lens, which is also called a "sheet magnifier" - works for some people, and you can usually get a mid-quality one at an office store for a few dollars.

https://www.officedepot.com/a/products/787170/Carson-Page-Magnifier ($11)

Look for "floor stand magnifiers" or "tabletop magnifier" - these would allow for hands-free operation.

Here is one:
https://lssproducts.com/led-full-page-magnifier-floor-lamp-3x/ ($100)

You might also want to try some headworn magnification glasses (craft / hardware stores often have these too):

https://www.stewmac.com/luthier-tools-and-supplies/tools-by-job/tools-for-maintenance/optivisor-headband-magnifier/ ($71)

https://www.activeforever.com/eschenbach-maxdetail-glasses ($126)

I personally like the MaxDetail glasses, as you can adjust the power of each eye separately.

Again, all these things work for some people and not for others - the only person who could tell if it works or not in this case is your grandfather. This is like buying shoes for someone else without them trying it on. See if you can try them with him first.

At the opposite end of the swimming pool, there are digital magnifiers like the Patriot Viewpoint for $3000. These can magnify things very nicely, block any distractions /light in the periphery, can read printed text aloud. These are often a good solution if none of the cheaper options work but the price (industry-wide) for these are nuts.

https://patriotvisionindustries.com/product/patriot-viewpoint/

A crafting lamp/magnifier could be helpful maybe?