A camera flash, uh-oh! 

A camera flash is fired directly into a person’s face, what is the end result? The light can reflect back from the subject’s retina, giving a red spot in the centre of the eye. Today, the majority of the cameras, mobile phones and tablets have a red-eye function that can avoid this.

Please check out the video, How to Use the Retouching Tools: Red-Eye Tool in Photoshop

Setting Up the Red-Eye Tool

1. You may need to zoom into the eye if you are unable to see the red-eye. Zoom in with the Magnify tool from the Toolbox (or keyboard shortcut) and position the mouse over the area containing the red-eye.
2. You will find the Red Eye tool hiding under the Content-Aware Move tool.
3. Click on the Content-Aware Move tool icon and hold your mouse button down until you see a new menu pop up. From the Toolbox, click the Red Eye tool or Click J or Shift-J.
4. The control panel changes to the Red Eye options  
5. If you place the Red Eye Tool on the image, the mouse will turn into the red-eye icon as seen to the right.
6. To remove: Pupil Size percentage controls how much of the red-eye in the pupil
   • Darken Amount will adjust the darkness of the pupil.
   • The default value for both of these options is 50%.
   • The Red Eye options allow you to alter the pupil size percentage value and the Darken Amount percentage value.
     
7. We can leave the Red Eye options to its default values.
8. Position the Red Eye tool over the red-eye and click.
9. Red eyes changed.