Parts and functions of the eyes?

Answer 1

ConjunctivaIs a thin protective covering of epithelial cells. It protects the cornea against damage by friction (tears from the tear glands help this process by lubricating the surface of the conjunctiva)CorneaIs the transparent, curved front of the eye which helps to converge the light rays which enter the eyeScleraIs an opaque, fibrous, protective outer structure. It is soft connective tissue, and the spherical shape of the eye is maintained by the pressure of the liquid inside. It provides attachment surfaces for eye musclesChoroidHas a network of blood vessels to supply nutrients to the cells and remove waste products. It is pigmented that makes the retina appear black, thus preventing reflection of light within the eyeball.Ciliary bodyHas suspensory ligaments that hold the lens in place. It secretes the aqueous humour, and contains ciliary muscles that enable the lens to change shape, during accommodation (focusing on near and distant objects)Iris

Is a pigmented muscular structure consisting of an inner ring of circular muscle and an outer layer of radial muscle. Its function is to help control the amount of light entering the eye so that:

- too much light does not enter the eye which would damage the retina

- enough light enters to allow a person to seePupilIs a hole in the middle of the iris where light is allowed to continue its passage. In bright light it is constricted and in dim light it is dilatedLensIs a transparent, flexible, curved structure. Its function is to focus incoming light rays onto the retina using its refractive propertiesRetinaIs a layer of sensory neurones, the key structures being photoreceptors (rod and cone cells) which respond to light. Contains relay neurons and sensory neurons that pass impulses along the optic nerve to the part of the brain that controls visionFovea (yellow spot)A part of the retina that is directly opposite the pupil and contains only cone cells. It is responsible for good visual acuity (good resolution)Blind spotIs where the bundle of sensory fibres form the optic nerve; it contains no light-sensitive receptorsVitreous humourIs a transparent, jelly-like mass located behind the lens. It acts as a 'suspension' for the lens so that the delicate lens is not damaged. It helps to maintain the shape of the posterior chamber of the eyeballAqueous humourHelps to maintain the shape of the anterior chamber of the eyeball

Answer 2

The Human eye is the most complex visionary among all mammals. A complete set of usefull fixes which helps the eye to give a most dimensional and advanced vision.

As a human eye is capable of seening the most wide spectrum of light. It can distinguish between colours which makes it special from all others.

Inside of our human eye is different layers which together forms a complete organ. Our eye is field with a organic protein which fills the inner eye space a protects all other vital parts from getting damaged due to any hamrages.

The most IMPORTANT part of our eye is LENS of it. The most important part and most delicate part also. The lens helps to dispers the light rays comming in the eye from any object and helps to make an image on the boundary of our eye. The lens is supported by CILLARY muscles which pulls or suppress the lens to adjust the focus image at the boundary.

The back eye is covered by three layers:- Sclera (the outer most), Choroid (the middle layer) and the Retina ( the inner most layer)

The Retina s where the image is focused from the lens. The retina is made up of colour sensitive cells. RODS and CONES are the types of colour sensitive cells. RODs are the intensity sensitive and they gets into schok if any white light with high intensty falls on them. This insensitiveness remains for an hour after that the RODs get active again. The cones are the colour sensitive cells. The both work together to for the image into a optic signal which is then sent to the brain from the back with the help of optic nerve.

The human eye is the most delicate and impotant part of human body. Hence the reflex given by it is in milli seconds.

Answer 3

The eye has many parts, each with a different function. Some of these parts include; the cornea which is in charge of protecting the inner parts of the eye from mechanical damage, the pupil allows light to enter the eye while the iris is the one that contains pigments of the eye and responsible for controlling the size of the pupil.

Answer 4

• Cornea: protects the eye.
• Optic Nerve: sends images to the brain.
• Iris: colored part of the eye.
• Pupil:
• Lens: focus objects near and far to make them clear.
• Ciliary Muscle: controls the amount of aqueous humor in the eye.
• Retina: converts light rays into electric signals which are sent to the brain.
• Vitreous and Aqueous humors: liquids in the eye.

Answer 5

Lens- the lens role is to focus on light and move towards the retina

Answer 6

The human eye is

Answer 7

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