You look in the mirror and notice that the dark circles in the middle of your eyes are bigger than usual. What's going on? Those dark circles are your pupils, the openings that let light enter your ...

Add Yahoo as a preferred source to see more of our stories on Google. Pupils often dilate in response to low light. Radu Bighian/Getty Images Dilated pupils mean that your pupils appear larger in size ...

Dilated pupils (mydriasis or fixed pupils) are when your eyes' pupils, which let light into your eyes, become wider. This can happen due to medications used during an eye exam (mydriatic drops), other ...

Dilated pupils (mydriasis) occur when the pupils open larger than usual. This normally happens in darker lighting to allow more light into the eye, but dilated pupils can also indicate an underlying ...

Many factors can influence pupil size. Typically, the pupils open up in low light situations to let in more light. However, some research suggests that attraction and mood might also cause pupil ...