Are holographic lenses practical?

I remember seeing some of these at a hologram gallery/store in Gatlinburg, Tennessee, some time before 1992 when the whole block burned down. Lots of expensive* holograms on display, but the ones that impressed me enough to still remember more than 20 years later were the microscope and telescope that you could look into. (The microscope one in the link might be the same one I saw–I’m pretty sure that the telescope one is the exact one.)

*The cheapest ones were IIRC over $50 and the most expensive several hundred, not in my high school budget at the time.