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__**Science Core Term 2 Project** __ //__Part (1) : The Human Eye __//

** The human eye itself is a big mystery that should be studied and should be known to everyone because of it's complexness and it's relation with cameras. We all love cameras and we most certainly love taking pictures of ourselves or the beautiful nature views and other interesting pictures. Sure, what you know right know is that you click a button and your camera takes the picture and there you have it, the picture itself. Well, there's much more mechanism inside the camera that you probably don't know about which is very much related to the human eye and how it works. In this part of the project, we will be explaining the miracle of the human eye. __The eye is analogous to a camera.__ **

** So let us get into the details and help you in actually knowing HOW the eye works like a camera o(^_^)o **

**First of all have a look at these two diagrams of the human eye and a typical camera :**

**as you can obviously see, there are big similarities between the two!** **THE FILM AND THE RETINA ARE OF THE SAME PURPOSE**

__**Now, before actually getting into details, you should know this simple similarities about both the eye and cameras :**__ **When your eye sees an object, the moment the light passes through the lenses of your eyes, it is actually upside down(reversed), not upright. Light passes through the lenses of your eyes and is printed on your retina, which is located behind your eyes as you can see in the previous picture. Here is where your hero, the brain, comes into action. It takes the image and turns it upside down for you so that it is upright and tells you what the image actually is! amazing isn't it?** **here's a simple picture to help you visualize it more:** **pretty much simple :)**

**Now for the camera. Notice anything "odd" in the below image of a camera?**

** YES! you're right, the image of the beautiful girl is upside down, exactly like how your eye analyses images upside down BEFORE going through the brain. ** ** so what exactly is the "brain" that rotates the picture so that it's upright? easy, the printer, which prints your picture upright. Also, if your camera has a screen which show's you the actual image once it's taken, your camera has it's own brain inside of it, it's mechanism. **

**N o w y o u a r e r e a d y t o g o i n t o t h e d e t a i l s o f h o w t h e h u m a n e y e w o r k s .**

**__The Cornea__** //** the cornea is basically your natural eye lens. It covers the front of your eye and is clear, it has no color and carries no blood. It is basically like a lens shutter of a camera. The cornea has an important role, which is focusing the lights that are deviated so that they can meet when they reach the inside of your eye to form the image. **//   **__The Iris and the Pupil__** //** the Iris and the Pupil are like two brothers or lovers, they work together. The Pupil is basically the black dot that that is surrounded by the Iris, which is the colored part of your eye, which is sometimes black, brown, green, hazel and such. The Pupil lets light into your eye. It gets bigger when you're in a dark place so that it can grasp more light and smaller when you're in a bright and lit place so that it protects your eye from damage. The Iris CONTROLS the amount of light that goes in your eye. **//   __**The Eye Lens**__ //** The lens directs the light so that it can reach the retina and is focused on the retina. It changes the proportions or shape of the object by bending the light so that the image that is formed on your retina is as clear as possible. **//   **__The Retina__** //**The retina is "the camera film". you obviously know what a camera film is and what it's function is. The picture is formed on the retina after going through all the previous stages.**// **__The Optic Nerve__** //**This nerve produces electrical signals. This nerve is almost like the cable that is connected from your ariel to the TV, it plays an important role so that you can actually SEE the image.**//

__**The three vision defects**__ These consist of Nearsightedness, Farsightedness and Astigmatism. all these three defects are a result of light not being properly focused on the thin layer behind the eye, called the Retina. This requires surgery to fix.

__Explanation of each in detail below__

__Nearsightedness:__

Basically, this is when the image is not formed ON your retina but in front of it because the eye is larger than the average human eye. as show in the below photo



The dotted line represents the average human eye size and the whole picture represents an eye of someone that suffers from Nearsightedness. Nearsightedness is the defect that causes a person to see objects that are nearby, better than objects that are far away as shown in the photo below.



__Farsightedness:__ You can probably guess that this is the exact opposite of Nearsightedness and you'd be correct. In this case, the image is formed BEHIND the retina rather than ON it because the eye is smaller than the average human size as shown below.



The dotted line, as mentioned before, represents the average human eye and the whole picture represents the eye of the victim of Farsightedness. Farsightedness causes the victim to see objects that are far away better than objects that are close by as shown below.

__Astigmatism: __This is a different defect from Farsightedness and Nearsightedness. This is caused by the misshape of the Cornea. The Cornea is usually round but with a person that suffers this defect, it's more like a football or oval as shown in the picture below.

<span style="display: block; font-family: 'Times New Roman',Times,serif; font-size: 140%; text-align: center;">**As you can see, the normal and the astigmatic look different. The astigmatic Cornea is defected. People that suffer with Astigmatism will have blurry vision and distortion of vision, as shown below.**

__<span style="color: #ff830f; font-family: 'Comic Sans MS',cursive; font-size: 160%;">**Lenses that help get rid of these defects!** __

<span style="display: block; font-family: Georgia,serif; font-size: 140%; text-align: center;">Of course, doctors and scientists have already found ways to get rid of these defects and the most recent and best ones are the Toric Contact Lenses. The Toric contact lenses have two great features or powers. there special Toric contact lenses for all three defects all made at different curvatures at different angles that fits the eye defect. They can either be soft or hard but most are soft. They take the shape of the wearer's cornea when placed on the cornea.



__**Part (2) : Cameras**__

//__<span style="color: #1958ff; font-family: Impact,Charcoal,sans-serif; font-size: 150%;">H o w d o c a m e r a s w o r k ? __//

First of all, the camera's most important role is to focus the light using the camera lens. there are various types of lens that are used for different purposes. Some for near objects and some for far. Then there are large and small apertures, the large apertures are used when a lot of light is needed to take a photo while small apertures restricts large amount of light to pass through. The shutter allows the light to pass for a certain amount of time, it controls the amount of light that passes. Faster shutter speed means that light will pass through for a short time and shorter shutter speed means much light will pass through. Often, faster shutter speed is for photography including sports where the objects are moving quickly. short shutter speed is used for still objects, like taking a picture of your classmate while he or she is doing a pose. While the shutter is open, the camera lens will be focusing light reaching the camera film which is located at the back of the camera. After the focusing of light on the film, there is a fast chemical reaction that takes place which causes the image to be printed/recorded on the film. If by mistake, you happen to expose the film to more light after the photo is taken, it might look blurry and unclear. Camera's have light-proof cartridges that stops light from getting in after the picture has been focused and recorded. After doing so, the film is then taken to a dark room, mostly RED lit room and is then exposed to chemicals that help the image form properly. <span style="color: #ff0505; font-family: 'Lucida Console',Monaco,monospace; font-size: 170%;">Below is are diagrams that explain how images are formed by cameras :

<span style="color: #eb0000; display: block; font-family: Impact,Charcoal,sans-serif; font-size: 170%; text-align: center;">AND



<span style="color: #1958ff; font-family: Tahoma,Geneva,sans-serif; font-size: 170%;">This concludes our research project for term 2 science core. But of course, there's no ending this project before giving credits to the resource pages that we visited in order to extract information whether it was pictures or actual information.

__<span style="color: #ff1431; font-family: Verdana,Geneva,sans-serif; font-size: 150%;">References : __ <span style="color: #f50028; display: block; font-family: 'Comic Sans MS',cursive; font-size: 140%; text-align: center;">1) http://en.wikipedia.org/wiki/Real_image <span style="color: #f50028; display: block; font-family: 'Comic Sans MS',cursive; font-size: 140%; text-align: center;">2) http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/OWENS/LECT1/node2.html 3) http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=1730 4) http://eugeneeyecare.com/conditions/What_is_Nearsightedness,_Farsightedness,_and_AstigmatismQQ.html 5) http://www.ehow.com/how-does_4567077_toric-lenses-work.html

//__** This web page has been done in honor to our teacher, Ms Lina Marouf, for always being a supportive and great teacher. **__//

- End of project - <span style="display: block; font-family: 'Courier New',Courier,monospace; font-size: 180%; text-align: center;">**- 1) SAIF SULTAN MOHAMMED SULTAN AL MHEIRI 1201090074** <span style="display: block; font-family: 'Courier New',Courier,monospace; font-size: 180%; text-align: center;">**- 2) SULTAN YOUSEF 1021080202** <span style="display: block; font-family: 'Courier New',Courier,monospace; font-size: 180%; text-align: center;">**- 3) RASHID TARIQ**

<span style="display: block; font-family: 'Courier New',Courier,monospace; font-size: 180%; text-align: center;">**12-04**