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Mahek Arora , asked a question
Subject: Science , asked on 1/10/14

parts of human eye and its functions

Vartika , added an answer, on 26/2/11
816 helpful votes in Science

Parts of Human Eye & Their Functions:

The human eye is a ball about 2.5 cm in diameter. It consists of the following parts:

1) Sclerotic: Sclerotic is the outer coating of the eye which is white in colour, that protects the interior of the eye and provides the shape to the eye.

2) Cornea: The front part of sclerotic is transparent to light and is termed as cornea. The light coming from an object enters the eye through cornea.

3) Iris: Iris is just at the back of cornea. This controls the size of the pupil. It acts like a shutter of a photographic camer and allows the regulated amount of light to enter the eye.

4) Eye Lens: Eye lens is a double convex lens with the help of which image is formed at retina by refraction of light.

5) Ciliary Muscles: The eye lens is held by ciliary muscles. Ciliary muscles help the eye lens to change its focal length.

6) Pupil: At the centre of the iris there is a hole through which light falls on the lens, which is called pupil.

7) Aqueous humour : The space between cornea and eye lens is filled with a transparent fluid called aqueous humour.

8) Vitreous Humour: The space between eye lens and retina is filled with a jelly like transparent fluid called vitreous humour.Eye Image

9) Retins : Retina serves the purpose of a screen in the eye, wherethe images of the objects are formed. Retina is at the back of the eye lens. Retins is made of light sensitive cells, which are connected to the optical nerve.

10) Optic Nerve: Optic nerve carries the information to brain.

11) Principal Axis

12) Blind Spot : The region of eye containing the optic nerve is not at all sensitive to light and is called blind spot. If the image of an object is formed in the blind spot, it is not visible.

13) Yellow Spot : The central part of retina lying on the optic axis of eye is most sensitive to light and is called yellow spot.

14) Eye Lids: Eye lids are provided to control the amount of light falling on the eye. They also protect the eye from dust particles etc.

Hope it will be helpful... :)

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Rudraksh Dixit , added an answer, on 1/10/14
114 helpful votes in Science

The given figure shows the structure of the human eye.

The human eye is roughly spherical in shape with diameter of about 2.3 cm. It consists of a convex lens made up of living tissues. Hence, human lenses are living organs contrary to the simple optical lenses.

Thewhite of the eyeis known as thesclera. It is the tough, opaque tissue that protects the outer layer of the eye.Irisis the coloured part of the eye, and thepupilis the black,

The following table lists the main parts of the human eye and their respective functions.

S. No.

Human eye part

Function

1.

Pupil

Opens and closes in order to regulate and control the amount of light

2.

Iris

Controls light level similar to the aperture of a camera

3.

Sclera

Protective outer coat

4.

Cornea

Thin membrane which provides 67% of the eyes focusing power

5.

Crystalline lens

Helps to focus light into the retina

6.

Conjunctiva

Covers the outer surface (visible part) of the eye

7.

Aqueous humour

Provides power to the cornea

8.

Vitreous humour

Provides the eye its form and shape

9.

Retina

Captures the light rays focussed by the lens and sends impulses to the brain via optic nerve

10.

Optic nerve

Transmits electrical signals to the brain

11.

Ciliary muscles

Contracts and extends in order to change the lens shape for focusing.

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Cm And Swathi .m , added an answer, on 22/1/17
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1)PUPIL:IT REGULATES AND CONTROLS THE AMOUNT OF LIGHT ENTERING THE EYE.
2)CORNEA:IT IS A TRANSPARENT PROTECTIVE LAYER IN THE HUMAN EYE.
3)IRIS: IT IS A DARK MUSCULAR DIAPHRAGM THAT CONTROLS THE SIZE OF PUPIL.
4)CILIARY MUSCLES: THESE CAN PROVIDE THE FINER ADJUSTMENT OF FOCAL LENGTH
5)CRYSTALLINE LENS : IT PROVIDES THE FINER ADJUSTMENT OF FOCAL LENGTH
6)RETINA : IT IS A LIGHT SENSITIVE SCREEN OF THE EYE ON WHICH REAL IMAGE AND INVERTEDOF THE OBJECT IS FORMED.
7)RODS: IT HELPS TO DETECT THE INTENSITY OF LIGHT.
8)CONES:CONES HELP US TO IDENTIFY THE COLOUR
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Esther , added an answer, 2 weeks, 5 days ago
2 helpful votes in Science
Cornea,
Iris,pupil,Retina,
Ciliary muscles,
Eye lens,Retina,
Optic nerve
 
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Shreya , added an answer, on 24/1/17
172 helpful votes in Science
yes Vartika has given a clear diagram and answer
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Arpitha , added an answer, on 28/2/15
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thanks for giving the answer.......
 
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Hiteshi , added an answer, 1 week, 4 days ago
9 helpful votes in Science
1. Cornea - Thin membrane through which light enters. 2. Aqueous Humour - Fluid mostly water to maintain correct pressure balance. 3. Pupil - Controls amount of light entering eye. 4. Iris - Dark muscular diaphragm that controls the size of the pupil. 5. Eye Lens - It is also called as crystalline lens. It adjusts it's focal length to focus objects at different distance on retina. 6. Ciliary Muscles - Responsible for changing curvature and focal length of eye lens. 7. Vitreous Humour - Jelly like fluid holds spherical shape of eye. 8. Retina - Light sensitive screen on which image is formed. It contains light sensitive cells called rods and cones which generate electrical signals. 9. Optic Nerves - Send the electrical signals to brain. 10. Yellow Spot (fovea) - It is the most sensitive part on retina where the sharpest image of an object is formed. 11. Dark Spot - It is the least sensitive part on retina where the image formed of the object cannot be seen by the eye because it contains no rods and cones.
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S.vignesh , added an answer, 3 days, 20 hours ago
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go to google and search
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Bhargavi Balasubramanian , added an answer, 1 week, 1 day ago
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Cornea -( it provides the refraction for light ray entering the eye. ) ;Iris - ( it controls the size of the pupil); Pupil - ( it controls the amount of light entering into the eye ) ; Ciliary Muscles - (it helps in regulating the size of the pupil ) ; Eye lens - (it focus incoming light rays on the retina ); Retina -(it helpsin formation of image on it); Aqueous humour- (it provides nutrition to the eye tissue ); Viterous Humous -( it helps to keep retina in place by pressing it against the choroid ).
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+917xxxxxx54 , added an answer, 1 week, 5 days ago
1 helpful votes in Science
My pencil ....m for ciliary MUSCLES ,p for PUPIL ,n for optic NERVE , C for CORNEA , i for IRIS and l for eye LENS
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Hiteshi , added an answer, 1 week, 4 days ago
9 helpful votes in Science
1. Cornea - Thin membrane through which light enters. 2. Aqueous Humour - Fluid mostly water to maintain correct pressure balance. 3. Pupil - Controls amount of light entering eye. 4. Iris - Dark muscular diaphragm that controls the size of the pupil. 5. Eye Lens - It is also called as crystalline lens. It adjusts it's focal length to focus objects at different distance on retina. 6. Ciliary Muscles - Responsible for changing curvature and focal length of eye lens. 7. Vitreous Humour - Jelly like fluid holds spherical shape of eye. 8. Retina - Light sensitive screen on which image is formed. It contains light sensitive cells called rods and cones which generate electrical signals. 9. Optic Nerves - Send the electric signals to brain. 10. Yellow Spot (fovea) - It is the most sensitive part on retina where the sharpest image of object is formed. 11. Blind Spot - It is the the least sensitive spot on the retina and an image formed on it is not seen by the eye because it contains no rods and cones.
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Arpitha , added an answer, on 2/3/15
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thanx//,,,,
 
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Surendra Singh , added an answer, 2 days, 17 hours ago
Out of sodium chlorine and silicon which one is metalloid
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Prithvi , added an answer, 2 weeks, 1 day ago
Refer ur text instead lazy ass!
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Ayush , added an answer, 2 weeks, 1 day ago
Our eyes are vital for seeing the world around us, but vision can be impaired by a number of medical conditions, as well as the ageing process. The eye is a slightly asymmetrical globe, about one inch (2.5 cm) in diameter. Picture of the Human Eye The front part of the eye (the part you see in the mirror) includes: The iris (the pigmented part) The cornea (a clear dome over the iris) The pupil (the black circular opening in the iris, which lets light in) The sclera (the white part) The conjunctiva (an invisible, clear layer of tissue covering the front of the eye, except the cornea) Just behind the iris and pupil lies the lens, which helps to focus light on the back of the eye. Most of the eye is filled with a clear gel, called the vitreous. Light projects through the pupil and the lens to the back of the eye. The inside lining of the eye is covered by special light-sensing cells, together called the retina. The retina converts light into electrical impulses. Behind the eye, the optic nerve carries these impulses to the brain. The macula is a small sensitive area within the retina that gives central vision. It is located in the centre of the retina and contains the fovea. Eye colour is created by the amount and type of pigment in the iris. Multiple genes inherited from each parent determine a person’s eye colour.
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Navneet Godara , added an answer, 1 week, 5 days ago
1 helpful votes in Science

Eye Parts

Description and Functions

Cornea

The cornea is the outer covering of the eye. This dome-shaped layer protects your eye from elements that could cause damage to the inner parts of the eye. There are several layers of the cornea, creating a tough layer that provides additional protection. These layers regenerate very quickly, helping the eye to eliminate damage more easily. The cornea also allows the eye to properly focus on light more effectively. Those who are having trouble focusing their eyes properly can have their corneas surgically reshaped to eliminate this problem.

Sclera

The sclera is commonly referred to as the "whites" of the eye. This is a smooth, white layer on the outside, but the inside is brown and contains grooves that help the tendons of the eye attach properly. The sclera provides structure and safety for the inner workings of the eye, but is also flexible so that the eye can move to seek out objects as necessary.

Pupil

The pupil appears as a black dot in the middle of the eye. This black area is actually a hole that takes in light so the eye can focus on the objects in front of it.

Iris

The iris is the area of the eye that contains the pigment which gives the eye its color. This area surrounds the pupil, and uses the dilator pupillae muscles to widen or close the pupil. This allows the eye to take in more or less light depending on how bright it is around you. If it is too bright, the iris will shrink the pupil so that they eye can focus more effectively.

Conjunctiva Glands

These are layers of mucus which help keep the outside of the eye moist. If the eye dries out it can become itchy and painful. It can also become more susceptible to damage or infection. If the conjunctiva glands become infected the patient will develop "pink eye."

Lacrimal Glands

These glands are located on the outer corner of each eye. They produce tears which help moisten the eye when it becomes dry, and flush out particles which irritate the eye. As tears flush out potentially dangerous irritants, it becomes easier to focus properly.

Lens

The lens sits directly behind the pupil. This is a clear layer that focuses the light the pupil takes in. It is held in place by the ciliary muscles, which allow the lens to change shape depending on the amount of light that hits it so it can be properly focused.

Retina

The light focuses by the lens will be transmitted onto the retina. This is made of rods and cones arranged in layers, which will transmit light into chemicals and electrical pulses. The retina is located in the back of the eye, and is connected to the optic nerves that will transmit the images the eye sees to the brain so they can be interpreted. The back of the retina, known as the macula, will help interpret the details of the object the eye is working to interpret. The center of the macula, known as the fova will increase the detail of these images to a perceivable point.

Ciliary Body

Ciliary body is a ring-shaped tissue which holds and controls the movement of the eye lens, and thus, it helps to control the shape of the lens.

Choroid

The choroid lies between the retina and the sclera, which provides blood supply to the eye. Just like any other portion of the body, the blood supply gives nutrition to the various parts of the eye.

Vitreous Humor

The vitreous humor is the gel located in the back of the eye which helps it hold its shape. This gel takes in nutrients from the ciliary body, aqueous humor and the retinal vessels so the eye can remain healthy. When debris finds its way into the vitreous humor, it causes the eye to perceive "floaters," or spots that move across the vision area that cannot be attributed to objects in the environment.

Aqueous Humor

The aqueous humor is a watery substance that fills the eye. It is split into two chambers. The anterior chamber is located in front of the iris, and the posterior chamber is directly behind it. These layers allow the eye to maintain its shape. This liquid is drained through the Schlemm canal so that any buildup in the eye can be removed. If the patient's aqueous humor is not draining properly, they can develop glaucoma.

 



 

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Trinton Stewart , added an answer, on 30/10/14

google exist lol

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Esther , added an answer, on 4/1/17
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The parts of the  human eye and functions are :
1.Corne
2.Pupil
3.Iris
4.Blind spot
5.Optic nerve
6.Yellow spot
7.Eye lens
 
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Srishti , added an answer, 4 days, 1 hour ago
Please find this answer

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Jigyasa Singh , added an answer, on 21/1/17
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Refer S.Chand for the Answer
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Faheem , added an answer, on 21/1/17
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thank u for the answers, i had the same question
 
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Upasana Das , added an answer, on 7/1/17
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thanks 4 d answers
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Maha Lakashmi , added an answer, on 26/12/16
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thank you it is very helpful for my exams
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Adharsh , added an answer, 3 weeks ago
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parts are sclera,cornea,iris,pupil,eye lens,vitreous humour,aqueous humour,retina,blind spot,optic nerve,cilliary muscles 

 
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Venkat Sai Ram , added an answer, on 11/12/16
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Yes
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Taimoor Faheem , added an answer, on 4/2/15
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it is so simple. I L y
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Upadhyay Ashish , added an answer, 3 weeks, 5 days ago
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Cornea,Iris,Pupil,ciliary muscles,suspensary ligaments,Eye lens,Retina,Blind Spot
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Waymae Lynn Ayson , added an answer, on 26/6/14
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what is the function of extraocular muscle?

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Akshal Jain , added an answer, on 18/8/14
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I don't know

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G.shashirekha , added an answer, on 2/1/14
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how do the lutein and corotenoids help eye protection

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