könnynyílás

Könnynyílás, also known as the pupil, is the circular opening in the center of the iris of the eye. It is the aperture through which light enters the eye and is regulated by the iris, the colored part of the eye. The size of the pupil is controlled by the muscles of the iris, which can dilate (widen) or constrict (narrow) in response to various stimuli.

The size of the pupil is influenced by several factors, including the amount of light available. In bright light, the pupil constricts to reduce the amount of light entering the eye, while in dim light, the pupil dilates to allow more light in. This process is known as the pupillary light reflex. Additionally, the pupil can be affected by emotions, drugs, and certain medical conditions.

The normal size of the pupil can vary depending on the individual and the lighting conditions. However, a pupil that is significantly larger or smaller than average may indicate a medical condition, such as glaucoma or a neurological disorder. In such cases, it is important to consult with a healthcare professional for proper evaluation and treatment.

Könnynyílás plays a crucial role in the visual system, as it allows the eye to adjust to different lighting conditions and helps to focus light onto the retina. Understanding the function and regulation of the pupil is essential for maintaining good eye health and vision.