The eyes are organs of the visual system that provide living organisms with vision, the ability to receive and process visual detail, as well as enabling depth perception, and allowing for several complex cognitive processes such as sight-related learning and adaptation to environmental changes. The structure of the eyes varies depending on the organism, but in general, they contain the following parts:

• Cornea: The transparent outer layer that covers the front of the eye and helps to focus light.

• Iris: The colored part of the eye that controls the amount of light that enters.

• Pupil: The black circular opening in the center of the iris that allows light to enter.

• Lens: A transparent structure behind the iris that helps to focus light onto the retina.

• Retina: The innermost layer of the eye that contains photoreceptor cells (rods and cones) that convert light into electrical signals that are sent to the brain via the optic nerve.

• Optic nerve: A bundle of nerve fibers that carries visual information from the retina to the brain.

Cosmetic products such as eye drops and creams may contain various ingredients, including preservatives, emulsifiers, and thickening agents. However, it is important to note that some ingredients may cause eye irritation or damage, depending on their concentration and other factors. Consumers should always read the ingredient list and follow the instructions carefully to avoid any adverse effects.