Comment by askvictor
Even for people with good eyesight, an instant read thermometer is a game changer. Completely takes the guesswork out of cooking meat perfectly, also excellent for cakes, potatoes, and more. There are very decent ones for less that $20.
I would add an immersion circulator to cook food sous vide as similarly impactful here, though getting a good thermometer is more necessary.
It's made meal prepping incredibly easy and food is always perfectly cooked. You never have to eat a dry or overcooked piece of meat again.