The iris is a circular, pigmented membrane that provides the eye its color and the opening in the center is the pupil of the eye.
The iris is made up of muscular fibers that control the amount of light entering the pupil so that you can see clearly. The iris accomplishes this task by making the pupil smaller in bright light and larger in dim light.
If you notice soft or hard yellow patches on the inside corners of your eyelids, you might have xanthelasma. They're made up of cholesterol that's under your skin. They aren't harmful, but if you're bothered by the way they look, there are treatments that can get rid of them.
Even though xanthelasma itself won't hurt you, it could be a sign that you're at higher risk for heart disease. So don't ignore this skin condition. Get it checked by your doctor.