What is the nasal Hemiretina?
Similarly, the surface of the retina may be divided into two halves by a vertical line drawn through the center of the fovea: a nasal hemiretina that lies medial to the fovea and a temporal hemiretina that is located lateral to the fovea.
What is a temporal defect?
Temporal visual field damage (VFD) is the common type of non-glaucomatous VF defects found in eyes with myopia. However, little is known about the factors associated with its progression.
What happens if the lateral geniculate nucleus is damaged?
Damage at site #4 and #5: damage to the optic tract (#4) or the fiber tract from the lateral geniculate to the cortex (#5) can cause identical visual loss. In this case, loss of vision of the right side. Partial damage to these fiber tracts can cause other predictable visual problems.
What are the steps of the visual pathway?
Visual Pathway
- Light enters the eye and projects onto the retina.
- Signals from the retinal photoreceptors → go to bipolar Bipolar Nervous System: Histology cells → then to the ganglion cells.
- Axons.
- Optic nerve.
- From the optic tract, most fibers synapse.
- From each LGN, neurons.
- Primary visual cortex.
What happens if there is a lesion in the right optic nerve?
Lesions involving the whole optic nerve cause complete blindness on the affected side, that means damage at the right optic nerve causes complete loss of vision in the right eye. Optic neuritis involving external fibers of the optic nerve causes tunnel vision.
What is Meyer’s loop?
The Meyer loop (also sometimes known as Archambault loop) is part of the inferior optic radiation that sweeps back on itself into the temporal lobe, just lateral to the temporal horn of the lateral ventricle.
What is temporal vision?
It is the condition for seeing interesting things such as spatial forms and patterns, colours and movements in the external world, and yet is not meant to be noticed in itself. Temporal aspects of visual processing have received comparatively little attention in research.
What is temporal field of vision?
The visual field is the part of space that a person perceives when fixing the eye on one point. Temporally, the field has a range of 95, nasally 65, superiorly 60, and inferiorly 70 degrees.
What is the lateral geniculate nucleus responsible for?
The lateral geniculate nucleus (LGN) belongs to the category of sensory projection nuclei of the thalamus and plays an essential role in normal visual processing.
What is the purpose of the lateral geniculate body?
The lateral geniculate body, a thalamic nucleus, provides a relay station for all the axons of the retinal ganglion cells subserving vision. Neurons from the lateral geniculate body project, by way of the optic radiations, to the pericalcarine cortex of the occipital lobe, which is the primary cortical area for vision.
What are the 3 visual pathways?
optic tracts. lateral geniculate body. optic radiation. visual cortex and its cortical projections.