Nervous layer and visual pathway

• What are the three layers of the eyeball?

  Fibrous layer, vascular layer, nervous layer
• What is the fibrous layer of the eyeball composed of?

  Sclera and cornea
• What structures are included in the vascular layer of the eyeball?

  Iris, ciliary body, choroid

  
• What are the components of the nervous layer of the eyeball?

  Pigment layer and neural layer
• What is the tunica fibrosa bulbi?

  Fibrous layer of the eyeball
• What is the tunica vasculosa bulbi?

  Vascular layer of the eyeball
• What is the tunica interna bulbi?

  Nervous layer of the eyeball
• What are the anatomical landmarks of the eyeball?

  Anterior pole, posterior pole, geometrical axis

  
• What is the surface area of the retina?

  About 1,094 mm²
• Where is the retina thickest?

  Near the optic disc at 560 µm
• Where is the retina thinnest?

  At the foveal floor at 100 µm
• What is the foveal position relative to the optic disk?

  11.8° or 3.4 mm temporal
• What is the size of the optic nerve head?

  1.86 × 1.75 mm
• What is the cross diameter of the macula?

  3 mm of intense pigmentation
• How much does one degree of visual angle equal on the retina?

  288 μm without correction for shrinkage
• How does pigmentation affect the retina's appearance?

  Lightly pigmented individuals have a lighter fundus
• What are the visible landmarks of the retina?

  Retinal blood vessels, optic disc, area centralis

  
• What is the arterial supply of the retina?

  Central retinal artery and posterior ciliary artery

  
• What is the venous drainage of the retina?

  Arcade veins to central retinal vein
• What are the zones of the retina?

  • Zone 1: Near periphery
  • Zone 2: Mid periphery
  • Zone 3: Far periphery

  
• What is the ora serrata associated with?

  Increased risk of retinal detachment
• What is the diameter of the optic disc?

  Approximately 1.5 mm

  
• What is the physiological cup?

  Depression in the center of the optic disc
• What is the normal cup-to-disc ratio (CDR)?

  0.3 to 0.4
• What does a CDR of 0.1 indicate?

  Cup is 90% smaller than disc
• What does a CDR of 0.3 indicate?

  Cup is 70% smaller than disc
• What does a CDR of 0.7 indicate?

  Cup is 30% smaller than disc
• What does a CDR of 0.9 indicate?

  Cup is 10% smaller than disc

  
• Where is the area centralis located?

  In the posterior pole, temporal to disc
• What is the diameter of the area centralis?

  5.5 mm
• What does the fovea correspond to in the visual field?

  5 degrees of visual field
• What is the macula lutea?

  Oval zone of yellow discoloration
• What is the diameter of the macula lutea?

  3 mm
• What is the foveal avascular zone?

  Capillary free zone in the center of fovea
• What is the diameter range of the foveal avascular zone?

  0.20 mm to 0.6 mm
• What is the foveola?

  Thinnest part of retina, highest visual acuity

  
• What is the diameter of the foveola?

  0.35 mm
• What is the significance of the umbo?

  Corresponds to the foveal reflex

  
• What is the external limiting membrane?

  Layer in the retina that supports photoreceptors
• What is the function of the retinal pigment epithelium (RPE)?

  Absorption of scattered light and visual pigment regeneration