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Visual Perception - Coggle Diagram
Visual Perception
Biological influences
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Achromatopsia
is complete color blindness. It’s usually congenital and caused by a problem in the eye or brain that prevents color perception. People with achromatopsia see only black, white, and gray. While it can be caused by cone abnormalities, damage to neural pathways or the brain can also lead to this condition.
Achromatopsia is a condition characterized by a partial or total absence of color vision.
People with complete achromatopsia cannot perceive any colors; they see only black, white, and shades of gray.
Ageing
Age influences both our physical and psychological abilities. Not only do our muscular appearances change with age, but so does our ability to perceive and interpret stimuli from our environment. Reading or driving can become increasingly different as you age. The maturing – or ageing – of our sensory perceptions, particularly our vision and hearing can affect our everyday life experiences and interactions.Biological ageing can affect our visial perception system, including the development of the above conditions.
Presbyopia
is the gradual loss of your eyes' ability to focus on nearby objects. This makes it difficult to focus on objects that are close, such as printed text or text on a computer screen. It's a natural, often annoying part of aging. Presbyopia usually becomes noticeable in your early to mid-40s and continues to worsen until around age 65. Symptoms – requiring bright light to see clearly, difficulty seeing in the dark, headaches and eye discomfort (strain or fatigue) Lens begins to loose elasticity and progressively looses the ability to focus light rays onto the retina. Cannot be reversed, but treated by wearing galsses or contact lenses.
Floaters
are tiny, gel-like climps of matte that float in the vitreous fluid that surrounds our eyes. Apepars like specks in our vsion, they are usually occur as part of the natural ageing process during mid-40s/ Caused when vitreous humour deteriorates and forms crystals. Harmless but can be annoying. People see tiny specks or squiggly lines that move quickly out of sight when you try to focus on them. Become noticeable when you look at a bright object.
Cataracts
Occur when the lens becomes cloudy due to the breakdown of proteins. Happens naturally as people age. Cataracts interrupts the process of focusing light on the retina, which results in blurred vision as well as difficulty seeing at night or in bright light. Ageing can contribute, but lifestyle factors (smoking, poor diet) and chronic diseases (diabetes and high blood pressure) also play a role. Treatment – wearing stronger eyeglasses and surgery.
Macula
is the region of the eye that has high concentration of rods and cones and is important for specific details (text, tiny movements, specific colours, telling the difference between faces).
Fovea is a section of this that has only cones so vision can be at its sharpest
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Glaucoma
affects the optic nerve and results in the loss of peripheral vision, which can lead to blindness. Damage to the optic nerve causes disruption of transmission from the eye ot breian. Often associated with increased intra-ocular pressure from the aqueous humour. (98% cases)
Genetics
Much of who we are and what we experience is determined by our genetic make-up and our visual perception system is no exception. Some inherited visual disorders are treatable if diagnosed early. Others are not as easily treated, and some can lead to blindness. Some can occur in childhood, others can appear later in adulthood.
Inherited disorders
Common inherited visual disorders that can occur in children are listed. Refractive errors can be caused by:
Eyeball length (when the eyeball grows too long or too short) Problems with the shape of the cornea (the clear outer layer of the eye) Astigmatism (uh-STIG-muh-tiz-um) is a common and generally treatable imperfection in the curvature of the eye that causes blurred distance and near vision. Astigmatism occurs when either the front surface of the eye (cornea) or the lens inside the eye has mismatched curves.
For adults, some cases of eye disorders such as glaucoma and age-related macular degeneration can also be attributed to genetic factors.
Congenital disorders
are present at birth and are quite rare. They can develop from genetic factors or diseases/deficiencies that arise during pregnancy.
Optic nerve hypoplasia – underdevelopment optic nerve
Retinitis pigmentosa
Genetic degenerative disease of the retina causing night blindness and gradual loss of peripheral vision. It is inherited causes by changes to genes that relay information of how to produce proteins required by photoreceptor cells. Genetic changes restrict the growth of these proteins and can cause the proteins to become toxic or dysfunctional. Rods then eventually the cones may die. Begins in childhood, children may not be able to see at night
The stages
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Transmission
Receptor cells send nerve impulses along the optic nerve to the primary sensory cortex in the occipital lobe.
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Interpretation
Memories, motives and values are used to give the stimulus context and make it make sense.