The optic nerve is a collection of nerve fibres that carries visual information from the retina to the brain. It is part of the visual system and can be thought of as an extension of the retina. The fibres in the optic nerve are axons of the ganglion cells in the retina. These axons are …
Blind spot is an area of the eye that is insensitive to light because it lacks the light-sensitive photoreceptor cells, called rods and cones, that are found in the rest of the retina. It is located at the point where the optic nerve leaves the eye. The blind spot is normally not noticeable because the …
Yellow spot is a patch of yellow pigmentation found on the ventral surface of the eye of some species of fish, including goldfish and koi. The yellow spot is thought to be a light-sensitive area that helps the fish detect food and predators.
The retina is a thin layer of tissue located at the back of the eye. It is made up of several layers of nerve cells and is responsible for sensing light and creating electrical signals that are sent to the brain, where they are interpreted as images. The retina also contains blood vessels and other …
The ciliary muscles are a ring of smooth muscles located around the circumference of the eye near the ciliary processes. They are responsible for controlling the shape of the lens, allowing it to become more or less curved and thus change the focus of the eye. The ciliary muscles contract and relax in response to …
The lens in the eye is a transparent, curved structure that helps to focus light onto the retina. It works in much the same way as a camera lens, allowing an image to be focused clearly onto the back of the eye. The lens is made up of proteins and water and is held in …
A pupil is the opening in the centre of the eye that allows light to enter the eye and reach the retina, which is the light-sensitive layer of tissue at the back of the eye. The size of the pupil changes depending on the amount of light entering the eye. When it is dark, the …
The iris is the coloured part of the eye that helps control the amount of light that enters the eye. It is a thin, ring-shaped muscular diaphragm that is located between the cornea and the lens of the eye. The size and colour of the iris is determined by the amount of melanin present in …
The choroid is a layer of tissue in the eye, located between the sclera and the retina. It is filled with blood vessels that nourish the retina. The choroid also helps to regulate the temperature of the eye and absorb excess light to prevent glare. It contains a pigment called melanin that gives the eye …
The conjunctiva is a thin, transparent membrane that lines the inside of the eyelids and covers the white part of the eye. It helps to keep the eye moist and healthy and provides a protective layer against dust, dirt, and other foreign particles. The conjunctiva also contains blood vessels that help to nourish the eye …