The iris is the colored, circular structure in the eye, surrounding the pupil. It’s a complex and highly specialized tissue that plays a crucial role in regulating light entry and supporting overall eye health.
Key characteristics:
- Color: The iris gets its color from melanin pigments, resulting in a wide range of colors and shades.
- Structure: The iris consists of two main layers:
- Stroma (front layer): Contains collagen fibers, blood vessels, and melanocytes.
- Epithelium (back layer): Contains pigment cells and muscles that control pupil size.
- Muscles: The iris contains two types of muscles:
- Sphincter pupillae: Constricts the pupil in bright light or during near vision.
- Dilator pupillae: Dilates the pupil in low light or during emotional arousal.
- Function: The iris:
- Regulates light entry into the eye by adjusting pupil size.
- Helps maintain optimal vision and protects the retina from excessive light exposure.
- Uniqueness: Each individual’s iris has unique patterns, colors, and textures, making it useful for identification purposes.
Importance: The iris plays a vital role in controlling light exposure to the retina, supporting optimal vision, and contributing to overall eye health.