Just make the AI go into “kill mode” after say… 5 minutes of being in the dark? Or better yet, have it as a difficulty setting.
Also, I would avoid having the dolls do the walking / covering eyes. Sure, have the footsteps and what not sound effects, but make it so that the dolls are sitting down, in a chair, in a corner, on the floor, etc… when the player looks at them. When the dolls attack, then they should of course, be standing / attacking.