These lenses allow you to change the appearance of your eyes at will, including color, pupil shape etc. They can create illusions as per Silent Image, but the illusion is limited to your eyes. This effect can even go as far as showing a scene that you remember.
The lenses also grant you advantage against gaze attacks and magical blindness effects.
The lenses also grant a +4 deflection bonus against gaze attacks, blindness effects and other attacks that target the eyes.