Correct red eye in Adobe Camera Raw

Open the photo where you want to correct the red-eye and select  .

Select Red Eye or Pet Eye from the Type drop-down menu. 

Drag a selection in the photo around the affected eye.

Camera Raw sizes the selection to match the pupil. You can adjust the size of the selection by dragging its edges.

In the tool options under the Histogram, drag the Pupil Size slider to the right to increase the size of the area corrected. By default, it's set to 50.  

(Only for correcting red eyes in pictures of pets) If necessary, select Add Catchlight. A catchlight provides a specular highlight in the image of an eye.

(Only for correcting red eyes in pictures of humans) Drag the Darken slider to the right to darken the pupil area within the selection and the iris area outside the selection.

Deselect Show Overlay to turn off the selection and check your correction.