Sense organs organon visus Dr Santosa Budiharjo Mkes

Sense organs: organon visus Dr. Santosa Budiharjo, Mkes. , PA(K)

Organon visus • Orbita: piramida empat sisi; basis-aditus orbita; canalis opticus-apex • Isi orbita: glandula lacrimalis, bulbus oculi, musculi bulbi, corpus adiposum orbitae, arteri, vena dan nervi

The visual field is the area of space in which all objects are visible simultaneously

• The visual field is the area of space in which all objects are visible simultaneously • In common terms, the visual field is the area of peripheral or side vision, although the object that is being fixated is also within the visual field. • The visual field is shown as an area drawn on a flat surface, with the boundary of the area being the farthest position that the person can detect a given object in any direction (EX binocular plot). • However, the "true" visual field is actually a 3 dimensional space, conceptualized as a half-sphere with an equal radius from eye to any point on the surface of the sphere. • This causes certain distortions of scale just like the distortions caused by projections of geography on maps.

• Vision is generated by photoreceptors in the retina, a layer of cells at the back of the eye. • The information leaves the eye by way of the optic nerve, and there is a partial crossing of axons at the optic chiasm. • After the chiasm, the axons are called the optic tract. • The optic tract wraps around the midbrain to get to the lateral geniculate nucleus (LGN), where all the axons must synapse. • From there, the LGN axons fan out through the deep white matter of the brain as the optic radiations, which will ultimately travel to primary visual cortex, at the back of the brain.

• absolute hemianopia blindness to light, color, and form in half of the visual field. • bilateral hemianopia affecting both eyes. • binasal hemianopia that in which the defect is in the nasal half of the visual field in each eye. • binocular hemianopia bilateral h. • bitemporal hemianopia that in which the defect is in the temporal half of the visual field in each eye. • complete hemianopia that affecting an entire half of the visual field in each eye. • congruous hemianopia that in which the defect is approximately the same in each eye. • crossed hemianopia heteronymous h. • heteronymous hemianopia that affecting both nasal or both temporal halves of the field of vision. • homonymous hemianopia that affecting the nasal half of the field of vision of one eye and the temporal half of the other.

strabismus

lagopthalmus

ptosis

• A stye (Lat. hordeolum = barleycorn) is a red, tender, painful, or itchy red bump, resembling a pimple, occurring on the eyelash. • It represents an infection (usually by bacterium Staphylococcus aureus) of an oil gland attached to the hair follicle • Chalazion is a bump on the eyelid that leads to obstruction in seeing things clearly. • It affects the eyelid glands known as Meibomian Glands. • Chalazion is known by many other names like Conjunctival Granuloma, Tarsal Cyst and Meibomian Cyst.

conjuctivitis

pterygeum