This extremely simple technique will make the natural color and detail within the iris pop.
STEP 1: With your image opened in Photoshop go to the Layers Panel and select ‘Create New Fill Or Adjustment Layer’, then ‘Solid Color’. In the color picker window input the value #828382.
Why this color? Well, it is the code for the Neutral Grey right at the midpoint between Black & White
STEP 2: Select the White Mask in the Solid Color Adjustment Layer, then press Command I (on a Mac) or Control I (on a PC) to invert the Mask.
STEP 3: Set the Blend Mode for the Solid Color Adjustment Layer from ‘Normal ‘to ‘Color Dodge’. Color Dodge has the effect of whitening the underlying Layer as it blends the two Layers together.
STEP 4: Then, grab a medium-sized brush using the Brush Tool with a Soft Edge. Set the Flow to about 20%. Using the Color Picker, make sure you have selected the color White. Now paint onto the iris in the areas around the iris, but without touching the pupil. If the effect is a little too much, then reduce the Opacity of the Layer.
