Table 2 Optical, physiological and anatomical data used in our physiological model.

From: Human rather than ape-like orbital morphology allows much greater lateral visual field expansion with eye abduction

Optical, physiological and anatomical data

Hypotheses

Corneal shape

Spherical

Corneal thickness

Nonea

Corneal radius of curvature

7.8 mm

Horizontal corneal diameter

12 mm

Air refractive index

1

Corneal refractive index

1.336b

Eyeball axial (antero-posterior) length

24.19 mm

External ante bi-canthal eyeball segment in the NOP

15.89 mm

Anterior chamber depth

3.15 mm

Eyeball rotation

Regular, around its centre

Eyeball abduction range

0 to 45°

Eyeball visual axis

Coincides with optic axis

Refraction of temporal rays by the cornea

Through pupil centre exclusively

Soft tissues thickness anterior to the temporal orbital rim

1 mm

Bi-canthal external distance

97.52 mm

Inter-ocular distance

63.73 mm

Orbital width in the NOP

40.17 mm

Average orbital opening angle value (human)

107.1°

Average orbital opening angle value (Pan)

98.7°

Average orbital opening angle value (Gorilla)

94.3°

Average orbital opening angle value (Pongo)

94.4°

Average orbital opening angle value (Hylobatidae)

101.6°

Lowest orbital opening angle value

85°

Highest orbital opening angle value

115°

  1. Abbreviation used: NOP = neuro-ocular plane.
  2. Notes:
  3. ain our model the air-cornea interface and the cornea-aqueous humor interface are combined into the air-aqueous humor interface, as if the cornea was infinitely thin and the aqueous humor bulged forward and was in direct in contact with the air.
  4. bAccording to point “a”, the cornea refractive index was set at 1.336 (and not 1.376), like aqueous humor.
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