Her eyes are dilated.

Tom's pupils are dilated.

How dilated is her cervix?

My eyes were dilated.

Roman women would dilate their pupils with belladonna because they believed this made them more attractive. Eye doctors still use belladonna during eye exams.

She's having contractions. How dilated is her cervix?

Tom's pupils became dilated.

I hate the drops doctors use to dilate my eyes for an eye exam.

One eye is dilated.