How Do We See?
Seeing involves more than opening our eyes. Through simple and fun experimentation the class will learn how the interaction of light, the eyes and the brain create the world we see.
How Do We See?
Our eyes are constantly feeding information to us. When we are born our eyes need time to get used to seeing and understanding what exactly it is that you are seeing. Given time and experience the eyes learn to take in light, focus it and send information to our brain.
All that you have experienced to this point has involved seeing and gaining an understanding of all that goes on around you. Most of what you see involves a knowing of it from previous experiences.
We perceive things. We build perception. Perception is not determined simply by looking at something but by our brain searching for the best conclusion of all the available information. When perception is wrong we are confused. Sometimes the eyes and brain come to the wrong conclusion and we get an illusion or hallucinate.
When you look at something your eyes are sending information about color, shape, movement, depth and distance to your brain. Then the brain puts it all together so that you can identify the whole object.
Seeing
The first thing one need understand about seeing is that if there is no light one cannot see. We are all able to see because light is bouncing off just about everything. There is more to seeing than meets the eye. When you look at an object you are seeing light that is bouncing or reflecting off of that object. Our eyes can take in light directly from a source, like looking at a light bulb, or indirectly after light bounces off of things like the moon.
When light bounces off of the surface of an object some light is absorbed and some light is reflected. We see only the light that is reflected or bounces off the object, so if you look at something that is blue that something you are looking at is absorbing all of the other colors and bouncing the color blue back at you.
The second thing to understand about seeing is the eye and brain connection. The eyes are one of the most important tools we have to gather information for our brain.
The Eyes
Light passes through a transparent part of the eye called the cornea. The cornea is a lens which bends light inward.
Another speaker, Margaret Livingstone delves into the visual aspect of our senses. Livingstone mentions how artists recognize things about vision that neuroscientists are not privy to until years later. Livingstone discussed the differentiation between color and lightness, and how the two contribute differently to a work of art. Color is thought of as “comparing activity” whereas light is thought of as “summing them.” Livingstone indicates that the visual system is subdivided into a ventral system and a dorsal system. The ventral system is responsible for object recognition, face recognition, and color. The dorsal system is responsible for navigating through the environment, special organization, and emotional recognition. The ability for humans to see distance and depth is carried via our colorblind part of our visual system. As a result, Livingstone concludes that one cannot see depth and shading unless the luminance is right to convey three-dimensional.
According to Dr. Vilayanur Ramachandran, in his movie “Secrets of the Mind,” our vision system is divided into two parts, one with our eyes, and the other with our brain. He also says that there are two different pathways in which our brain uses to “see.” One of these pathways, he calls the evolutionary new pathway (the more sophisticated pathway) in which our eyes see, then the information is sent to the thalamus, and eventually entering the visual cortex of the brain. This pathway is the conscious part of seeing. The other pathway Dr. Ramachandran says is more prominent, as well as evolutionarily primitive. An iguana uses this system of seeing. In this second pathway, information enters through the eyes, and then is sent to the brain stem, which in turn relays the information to the higher center of the brain. Dr. Ramachandran says that this second system is used to orientate our eyes to look at things, especially movement. Dr. Ramachandran has looked at patients with what is known as blind-sight to form his hypothesis.
Blindsight is often understood as supporting certain claims concerning the function and the status of the phenomenal qualities of visual perceptions. In this talk I am going to present a short argument to show that blindsight could not be understood as evidence for these claims. The reason is that blindsight cannot be adequately described as a special case of seeing. Consequently, it is not possible to draw inferences from it concerning the role of the phenomenal qualities for seeing.
The Webster dictionary determines perception to be knowledge by the senses and/or life that have an influence on people’s perception (Parker, 2010). The way people perceive things is based on their five senses. The sense of sight was the main sense used in the following experiment, as well as a person’s memory. Eyes tell people what they want to see and want to know. They tell you how to conceive a person and their behaviors as well as their reactions. It essentially judges the world around you. One is able to perceive how a person reacts to certain situations entirely by watching them. Perception applies to the interpretation of what we take in through our senses, in terms of optical illusions. Optical illusions happen because our brains are trying to define what it is that we envision and make sense of the world around us. If perception has no foundation in a person’s experience, a person may literally not perceive it. Perception is a method by which people set up and define their sensory impressions to give significance to their environment. Critical thinking is something we all do, because the regularity may range from person to person.
seem to be one way, it is another. For example, the Muller-Lyer illusion makes people see
Everyone has a different perception than another, such a different perception that should be taken into account by other people. Whether people are blind or crazy, some people of this world are impaired so their lives are limited. The unknown can be very mind-boggling to these impaired people. Though at the same time there is a strong possibility that there are also even more unknown things to unimpaired people. Plato’s “The Allegory of the Cave” and “Seeing” by Annie Dillard suggest that knowledge and reality are both a matter of perception based on experiences; and as such, great care should be taken by anyone who attempts to redefine the perceptions of another.
What we see in some things can based on our past experiences and things we’vewe have seen before. If you ever look at the clouds during the day and try to decide what you see and then ask someone else what they see it’sit is about very little chance that everyone will see the same thing. This is what I think of
The four main components of the eye that are responsible for producing an image are the cornea, lens, ciliary muscles and retina. Incoming light rays first encounter the cornea. The bulging shape of the cornea causes it to refract light similar to a convex lens. Because of the great difference in optical density between the air and the corneal material and because of the shape of the cornea, most of the refraction to incoming light rays takes place here. Light rays then pass through the pupil, and then onto the lens. A small amount of additional refraction takes place here as the light rays are "fine tuned" so that they focus on the retina.
normally convinced that what we see and feel is truely there. If this is a
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 that are collectively 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 extra-sensitive area within the retina that gives central vision. It is located in the center of the retina and contains the fovea, a small depression or pit at the center of the macula that gives the clearest vision. The blind spot is at the exit point of the optic nerve, at this point there are no rods or cones, and so all the light directed here are of no use. Eye color is created by the amount and type of pigment in the iris. Multiple genes inherited from each parent determine a person’s eye color. Though the eye is such a wonderful organ, it is also prone to diseases, infections, and other problems that could be minor or major, and could lead to blindness or poor
Each one of us lives in our own unique world of perception. As individuals, we may experience life in an entirely different way through our senses and life experiences. Therefore, perception can be tricky since it is very personal to each one of us. According to the Merriam-Webster online dictionary, perception has three meanings; (1) “the way you think about or understand someone or something,” (2) “the ability to understand or notice something easily,” and, (3) “the way that you notice or understand something using one of your senses” (2014, para. 1). C.S. Lewis said, “What you see and what you hear depends a great deal on where you are standing. It also depends on what sort of person you are” (n.d., para. 11). In other words,
Visual perception plays a big part on how we perceive life. If we didn't have perception I don't know where we would be now.
The duality of how light behaves depends in which state light is being observed and how it interacts with an object 's surface. It is neither just a wave or a particle, they coexist and react to objects electrons and protons within their atoms. Animals, plants and our sky are examples of how light reacts and are seen.
The information gathered by the eye is processed by the brain, creating a perception that in reality, does not match the true image. Perception refers to the interpretation of what we take in through our eyes. Optical illusions simply trick our brains into seeing things which may or may not be real. (What is an Optical Illusion)
This reflected light passes through the lens and falls on to the retina of the eye. Here, the light induces nerve impulses that travel through the optic nerve to the brain, where it makes an image of the object, and then that image is passed on to muscles and glands.The eye is well protected. It lies within a bony socket of the skull. The eyelids guard it in front. They blink an average of once every six seconds. This washes the eye with the salty secretion from the tear, or lachrymal, glands.