Visual perception is the capacity to comprehend one’s surroundings through one’s sense of sight. The sequential step that takes place during visual perception is termed the visual process. Here, let’s have a brief look at the components and steps that comprise the visual pathway.
Table of Contents
Vision – Process
The sequence of events that take place during visual perception is known as the visual process. During the visual process, the retina receives a focused image of an object seen by the eyes, producing a visual perception of that object. The nerve pathway that carries impulses from the retina’s visual centre to the eye is known as the optic pathway or visual pathway.
Visual Receptors
The visual receptors are made up of rods and cones that are found in the retina of the eye. Dendrites of the bipolar cells in the inner nuclear layer of the retina form synapses with fibres from the visual receptors.
Rods have a low threshold and are highly light-sensitive. Therefore, scotopic vision, night vision, and dim light vision are all caused by the rods. The threshold for light stimulus in cones is high. The cones can only detect bright light. Hence cone cells are referred to as bright light, daylight, or photopic vision receptors as a result.
Visual Pathway of Eye – Steps
Like a camera, the eye focuses and captures light. The cornea is where light enters the eye. The light enters the pupil from the cornea. The iris, or coloured portion of your eye, controls how much light passes through.
The light then strikes the transparent eye structure known as the lens, where it is focused on the retina.
The image appears to be upside down when it finally reaches the retina. It comprises the nerve layers that line the back of the human eye and is sensitive to light.
The visual cortex in the brain receives signals of light, dark, and colour from the optic nerve and assembles them into images.
Also Check: Structure of Eye MCQs for NEET
Processing of Visual Information
The visual pathway comprises the following six components:
- Optic nerve – The axons of the retina’s ganglionic cells form the optic nerve.
- Optic chiasma – Optic chiasma refers to the location where the fibres of the optic nerve cross.
- Optic tract – It is a continuation of the optic nerve. Information is transmitted from the optic chiasma to the lateral geniculate body via the optic tract.
- Lateral geniculate body – The majority of the optic tract’s fibres come to an end in the lateral geniculate body, which serves as the brain’s subcortical centre for visual perception.
- Optic radiation – Optic radiation is created when fibres from the lateral geniculate body pass through the internal capsule of the brain. It typically ends in the visual cortex.
- Visual cortex – The medial surface of the occipital lobe contains the visual cortex, the primary cortical centre for vision.
Visual Pathway
Visual receptors in retina →Optic nerve →Optic chiasma →Optic tract →Lateral geniculate body →Optic radiation →Visual cortex
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