mirar vs ver
Mirar is looking (actively directing your gaze). Ver is seeing (the result — what registers in your eyes).
mirar
To look at — you're directing your attention intentionally.
Mira por la ventana.
Look out the window.
An active choice to direct your gaze. You're telling someone to look.
No me mires así.
Don't look at me like that.
The gaze is intentional and directed. Mirar = the act of looking.
Están mirando el menú.
They're looking at the menu.
Active, deliberate attention. Ver menú would mean they can see it — different thing.
ver
To see — what your eyes register, or watching something over time (TV, film).
¿Has visto mis llaves?
Have you seen my keys?
Not asking if they looked — asking if the keys entered their field of vision.
Ver la televisión.
To watch TV.
Watching TV uses ver, not mirar. Fixed phrase — don't swap them.
Desde aquí no se ve nada.
You can't see anything from here.
Visibility — what the eyes can register from a position. Nothing active about it.
Tricky bit
¡Mira! = Look! (directing attention). ¿Ves? = Do you see? / You see what I mean? (comprehension or visibility). In conversation, '¿ves?' is constantly used to check understanding — like 'you know?' in English.