with one eye on (something/someone)

have/keep one eye on (something/someone) - to give part of your attention to one thing or person while also giving your attention to something or someone else.

She sat writing her letter with one eye on the clock.

• there's method in madness
• there's method in someone's madness
• There's more than one way to skin a cat.
• there's much to be said for
• there's much to be said for doing something
• there's much to be said for something
• There's no accounting for taste!
• there's no law against
• there's no law against doing something
• there's no law against something
• There's no peace for the wicked!
• There's no rest for the wicked!
• There's no smoke without fire.
• There's no such thing as a free lunch.
• there's no telling
• there's nothing to it
• There's nothing to it.
• There's no time like the present.
• There's no time to lose.
• There's no two ways about it.
• There's one born every minute.
• There's one for the books.
• There's safety in numbers.
• there's the rub
• There's the rub.