It is real. I watched my aunt use it over a decade ago. I can only imagine how much it has improved since then.

It also costs like $20,000, which is why insurance covers it (sometimes)

Extremely precise. https://eyegaze.com/users/als/

Eye movement tracking tablets have existed for ~15 years. My aunt had ALS and used one in 2007 when she couldn’t speak anymore. It’s basically a tablet that tracks your eye movement. There’s a digital keyboard and it recognizes what letters you’re looking at in what order, so you can form sentences and have it speak for you. They’re very expensive but insurance will often cover it. You should look into it

Edit: here’s a link for the one my aunt used https://eyegaze.com/products/eyegaze-edge/