Retouching eyes unnaturally is a great way to ruin a good portrait. Here’s a 14-minute tutorial by photographer Dani Diamond that shows how you can easily retouch eyes with a natural look using Photoshop.
To get a natural look, Diamond says it is crucial to understand how light interacts and works with the human eye. Consequently, he begins the tutorial with a useful description of how to read light within the iris of the eye – something that other similar technique videos don’t appear to address.
Sharpening the eyes is the first step you should do, and by using layer masks you can paint your changes into the target areas. Use a brush that isn’t set at 100% opacity and you’ll find that you can be more gentle and gradual with the adjustment.
When lightening the eyes, Diamond says that you should brighten the area opposite the catch light. This is because light enters into the eye in the bright area, and “exits” through the opposite side. If you don’t lighten with this rule in mind, things can look very unnatural and “alien.”
Diamond finishes his tutorial with a screen recording of a start-to-finish edit using these techniques, allowing you to see an uninterrupted workflow.