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Human beings have binocular vision, i.e.

The eye is one of the five sense organs of human beings that are equipped to receive light and convert it to visual impulse. Human beings have binocular vision, i.e. vision is created by both the eyes perceiving a single three-dimensional image of the object when light reflected from it falls on the retina and the impulse is carried by the optic nerve to the brain where it is processed. The eyes sit in two bony cavities called eye sockets, protected by the upper and lower eyelids and eyelashes.

The human eye consists of the following structures: The Three Coats: The human eye is surrounded by three coats, the sclera, the choroid and the retina. The sclera is the fibrous outermost layer which is white and opaque in the posterior 5/6th portion. The anterior 1/6th portion of the sclera is transparent and is known as the cornea. While the posterior part ensures that light entering the eye does not pass through, the anterior portion allows the entry of light into the eye. The choroid is the middle layer which is supplied with blood vessels. The anterior part of the choroid forms the annular pigmented iris. The opening of the iris is known as the pupil of the eye. Ciliary bodies behind the iris remain attached to the lens by suspensory ligaments. They together help in the attachment and in changing the shape of the lens. The innermost layer is known as the retina which is provided with photosensitive cells. These cells are rod and cone cells which are responsible for receiving dim and bright light respectively. Cone cells are also sensitive to colour and help in coloured vision. The central portion of the retina where light entering perpendicular to the eye has the highest concentration of cone cells and is called the macula lutea. The centre of the macula lutea is called fovea centralis or yellow spot and is responsible for the brightest and sharpest vision. The Spaces in the Eye: The space between the iris and the cornea is filled with a fluid called the aqueous humor and the space between the retina and the lens is filled with vitreous humor. They help in maintaining the pressure and shape of the eyeball and also act as a refractive medium of the eye. Lens: The lens of the human eye is a transparent bi-convex structure which acts as the main refractory medium focusing the light on the retina. A basement membrane called the lens capsule surrounds the lens. The main bulk of the lens is made up of lens fibres. The anterior side of the lens has a layer of lens epithelium between the lens capsule and the outermost layer of the lens fibre. [Image Will be Uploaded Soon]

Or if framed alternatively, the question would be how are we able to see an object? – The answer is explained below with the help of a schematic diagram: [Image Will be Uploaded Soon] The image of an object is formed on the retina situated in the inner eyeball when light rays reflected from that object converge at the cornea after passing through the lens. Light rays from the topmost point and bottom of the object in question are traced to the eye where they produce an inverted real image right on the retina.

The human eye is a super-specialised sense organ that endows us with vision. It reacts with light and allows colour vision, light vision, and depth vision.

Answer: The different refractive media of the human eye are cornea, aqueous humor, lens, and vitreous humor. They work in synchrony to focus the light on the yellow spot of the retina.

Answer: Five interesting facts about the eye are as follows:

Answer: The innermost layer is known as the retina. It is provided with photosensitive cells. These cells are rod and cone cells which are responsible for receiving dim and bright light respectively. Cone cells are also sensitive to colour and help in coloured vision. The central portion of the retina where light entering perpendicular to the eye has the highest concentration of cone cells and is called the macula lutea. The centre of the macula lutea is called fovea centralis or yellow spot and is responsible for the brightest and sharpest vision. The peripheral regions of the retina have more rod cells and thus help in blurred vision.

Answer: There are cone cells on the retina that perceive the colour(s) of the image. There are different types of cones responsible for red, green r blue vision.

Answer: There are 6 main muscles in the eye. These are- medial rectus, lateral rectus, superior rectus, inferior rectus, superior oblique, and inferior oblique.

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