powieki

Powieki, also known as eyelids, are folds of skin that cover and protect the eye. They are composed of skin, muscle, and connective tissue, and they play a crucial role in maintaining eye health and vision. The primary function of the eyelids is to shield the eye from foreign objects, dust, and excessive light. They also help to distribute tears evenly across the surface of the eye, keeping it moist and clean. This constant lubrication is essential for preventing dryness and irritation, which can impair vision and lead to infections.

The blinking reflex, a rapid and involuntary closing and opening of the eyelids, is a vital protective mechanism. It can be triggered by sudden bright lights, a perceived threat, or even as a response to irritants. Blinking also helps to sweep away debris and refresh the tear film. In addition to their protective role, eyelids contribute to facial expressions, conveying emotions such as surprise, happiness, or sadness. The muscles within the eyelids allow for voluntary control, enabling actions like winking or deliberate eye closure. Eyelid anatomy includes the upper and lower lids, with the eyelashes along their edges serving as an additional barrier against dust and small particles. The inner surface of the eyelid is lined with a transparent membrane called the conjunctiva, which also covers the white part of the eye.