Evaluate The Human Visual System

The human visual system allows us to make sense of our environment. This system requires communication between the main organ (the eye) and the core organ (the brain) to understand external stimuli. The eye is extremely complex and requires various components for it to complete its function. The eye has 3 main layers the sclera, which maintains and supports the shape of the eye; the choroid, which provides oxygen and nourishment to the eye and includes the pupil, iris, lens; and the retina, which allows us to piece images together and includes two types of photoreceptors, cones and rods which helps the human eye see across multiple magnitudes. Rodieck, 1998 found that Rod cells are responsible for our night vision; they react well to dim light. Rods are found mostly in the outer regions of the retina. Cone cells are concentrated in a central region of the retina; they are responsible for tasks like reading, and also for colour vision. Cones can be categorized into three types, depending on how they respond to red, green, and blue light. In combination, these three cone types enable us to perceive colour. …show more content…
Bottom- up processing is also known as data-driven processing, as this theory believes that it begins with the stimulus itself. Implying that processing is carried to the retina then directly to the visual cortex. Top- down processing is the use of contextual information in pattern recognition- ‘the big picture’ where by images or words provide a context to prompt an understanding to the visual information. In most psychologists argue that in most cases perception uses both processes as they argue with the use of both it allows us to organise the information given to us and make sense of