The uvea is made up of a layer of blood vessels, a muscular ring that surrounds your pupil, and the iris, the colored part of your eye. Together, they help your eyes focus so you can clearly see ...

Medically reviewed by Johnstone M. Kim, MD A coloboma is a missing piece of tissue in a person's eye. It is a congenital ...

Medically reviewed by Christine L. Larsen, MD Medications, trauma, and medical conditions can lead to abnormally small pupils ...

That coloured circle is called the iris and the black spot in the middle is the pupil. This is the part of the eye that lets the light in. Lights out please! When it’s dark, muscles in the iris ...

Muscles in the colored part of your eye, your iris, then work to constrict or dilate your pupils, letting in more or less light as needed. 2. Medication "Certain medications can interfere with the ...

MIT engineers have made a breakthrough in this area—they’ve developed a method to grow muscle tissue that contracts in ...

Cornea Tough, transparent covering over the front part of the eye. Convex in shape. Refracts light as it enters the eye (by a fixed amount). Iris Coloured part of the eye that contains muscles.

Retinal vs. iris scans Often confused with a retinal scan, iris recognition systems capture an image of the eye, and then analyse the coloured part around the pupil that you see on the front of the ...