The eye; the most complicated sense organ
General – Introduction to the subject
A. Adaptation of sense organs to our biological evolution
Sense organs, as the other organs, are the result of our continuous biological evolution and are built is such way so they can meet our needs.
B. The electromagnetic spectrum and what we are able to see
The electromagnetic spectrum contains a large width of energy areas but we are able to see only a small part of this spectrum, the visible light spectrum.
Figure 1
As you can see the visible area is between the Ultra-violet and Infra-red areas.
With a simple experiment we can show than light from sun can be separated into this light spectrum. Using a prism and a piece of paper with a hole on it (the hole helps us abridge the light into a single beam) and point the beam onto the prism. On the other side we place another piece of paper and we can see the light spectrum.
C. What we see differs from what animals see
It’s a fact that what see differs from what animals see. Humans see the world in a totally different way that bees see for example.
In these pictures you can observer that humans can see the entire visible light spectrum and would be able to see the rich greens of the grass on the left, prairie dogs (=τρωκτικά) and squirrels are red/green color blind, and only perceive the blues, yellows, and grey of the landscape.
Figure 2
Sharks do not possess the same variety of photoreceptors as humans. They have few retinal cones, and as a result, most have no color vision. Also, they have much larger rod receptors (which pick up light), with fewer numbers of them, so their vision is much less acute (=οξέια όραση) than ours.
Figure 3
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...he distinction of colours. Most common is the weakness to distinct red-green colour.
Special tests allow the diagnosis of achromatopsy. Without taking these special tests you won’t be able to know whether you have achromatopsy or not.
Figure 10
Figure 11
The eye illusions
Our visual perception cannot always be trusted. The components of an object can distort the perception of the complete object. Our mind is the final arbiter of truth. Most optical illusions are the result of
1) Incongruent design elements at opposite ends of parallel lines,
2) Influence of background patterns on the overall design,
3) Adjustment of our perception at the boundaries of areas of high contrast,
4) Afterimages resulting from eye movements or from kinetic displays
5) Inability to interpret the spatial structure of an object from the context provided by the picture.
One wonders what takes place in the brain to cause such phenomenal differences in perception. The cause is unknown for certain, like many things in the realm of science it has not been researched nearly enough, but there are some indications.
Different wavelengths of light determine what colors we see in fish and other organisms. For instance, the changes of season affecting length of daylight triggers many species in the wild to change into their extreme breeding dress. Scientific studies exhibit numerous reports of fish that faded in color after becoming blind, an observation that would have some implications for fish kept in the dark.
ABSTRACT: The aim of this paper is to defend a broad concept of visual perception, according to which it is a sufficient condition for visual perception that subjects receive visual information in a way which enables them to give reliably correct answers about the objects presented to them. According to this view, blindsight, non-epistemic seeing, and conscious visual experience count as proper types of visual perception. This leads to two consequences concerning the role of the phenomenal qualities of visual experiences. First, phenomenal qualities are not necessary in order to see something, because in the case of blindsight, subjects can see objects without experiences phenomenal qualities. Second, they cannot be intentional properties, since they are not essential properties of visual experiences, and because the content of visual experiences cannot be constituted by contingent properties.
The electromagnetic spectrum is a range of different types of radiations, this is energy that travels and spreads out as it goes. This range involves more than just visible light- small portion of the spectrum detected by the human eye- it goes beyond what the human eye cannot see. The two most important characteristics of the spectrum are wavelength and frequency. The electromagnetic spectrum can be divided into three different parts: the theory of visible light, the range of the electromagnetic spectrum, and how it benefits mankind.
seem to be one way, it is another. For example, the Muller-Lyer illusion makes people see
Actually, many people don’t understand their visual system and don’t know how it functions. Most people believe if they can see the world, object clearly that means their visual system is perfect.
One reason why seeing is not believing (perception is not reality) is magic. Magic is one of the things in this world that can trick the eye of a human. In “Magic and the Brain” by Susana Martinez-Conde and Stephen L. Macknik, a magician named the Great Tomsoni changed the color of a dress
When we think of color vision, we imagine the variety of colors the human eye can see. Perhaps people may believe having color vision is a huge benefit for animals as opposed to having dichromatic or even monochromatic vision. If that would be the case, then why do not all the animals have color vision? A thought to keep in mind is what is the purpose of seeing color for animals. We will dive deeper into how color vision may play a role in the lives of animals and humans. The different groups of animals we will examine are the marine animals, wild Neotropical monkeys, primates, and humans as well.
Light is both part particle and part wave. Light is “the electromagnetic radiation that may be perceived by the human eye”. It consists of photons, which are massless bundles of concentrated electromagnetic energy. Light’s lower frequency is red, and the higher frequency is blue. Like sound, light has frequencies humans can’t detect. Ultraviolet light is at a frequency higher than violet, and infrared is at the frequency lower than the red of visible light. We get UV (ultraviolet) rays from the sun, and infrared is used in night vision to see better.
The simple optical illusions used by Ariely show us just how easily our senses can lead our judgments to be distorted. The first illusion was an animation of Shepard’s Tables; an example of size-constancy expansion first published by Roger Shepard as “Turning the Tables”. We know the two tables are the same length but yet why does one table appear to be longer than the other? In this case it is because the angles suggest depth and perspective and the brain wrongly believes one table is longer and while the other in shorter. It is interesting that despite us knowing that the tables are in fact the same length, we still perceive them to be different lengths; despite us knowing the truth, we could not get our minds to see reality as it really is. In the second example, Ariely shows the ...
We use our ears for the hearing sense, and we use our eyes for vision.
Most of the light energy from the sun is emitted in wavelengths shorter than 4,000
There are many different Visual Perception principles in perception. The main principles are Gestalt. Gestalt is a German word meaning 'form' or 'shape'. Gestalt psychologists formulated a series of principles that describe how t...
Light is what lets you experience colour. The pigment of the retina in your eyes is sensitive to different lengths of light waves which allows you to see different colours. The wavelengths of light that humans can see are called the visible colour spectrum.
The Eye is the organ of sight. Eyes enable people to perform daily tasks and to learn about the world that surrounds them. Sight, or vision, is a rapidly occurring process that involves continuous interaction between the eye, the nervous system, and the brain. When someone looks at an object, what he/she is really seeing is the light that the object reflects, or gives off.