Apps:

Pixlr EDITOR

Steps:

1. Choose a eye's image.

2. Open https://www.pixlr.com/editor/ or https://www.pixlr.com/ and then scroll down to find Pixlr Editor and click launch web app.

3. From the dialogue box that appears, open image that you chose previously.

4. Add new layer.

5. Choose Marquee Tool > Elliptical Marquee. 

6. Marquee the eye ball so it looks like:

7. Color the area as required:

8. Deselect All.

9. Change the mode to OVERLAY for darker effects and SCREEN for lighter effects.

10. Erase the extra parts, the highlights and the pupil.

11. Save.

O R I G I N A L :