Refractive state, depth of focus and accommodation of the eye of the California ground squirrel (Spermophilus Beecheyi)

doi:10.1016/0042-6989(84)90180-9

Vision Research

Volume 24, Issue 10, 1984, Pages 1261-1266

https://doi.org/10.1016/0042-6989(84)90180-9 Get rights and content

Abstract

Retinoscopy and electrophysiological refraction were performed on 55 and 24 faraccommodated eyes of California ground squirrels (Spermophilus beecheyi), respectively. These two indices were highly correlated, revealing the eye of this animal to be roughly emmetropic (−0.25 to −0.13 D). Depth of focus was assessed by measuring the effect which defocusing produced on the spatial resolving power of 32 optic nerve fibers. Depth of focus of the ground squirrel eye for a pupil diameter of 2.5 mm is estimated to be ± 1.6 D, but will increase rapidly for smaller pupils. Accommodation in eleven ground squirrels ranged from 2 to 6 D, with a mean value of 3.9 D.

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Refractive state, depth of focus and accommodation of the eye of the California ground squirrel (Spermophilus Beecheyi)

Abstract

Vision Res.

Vision Res.

Vision Res.

Vision Res.

Vision Res.

Vision Res.

Vision Res.

Anim. Behav.

Vision Res.

Vision Res.

Retinal ganglion cells responding selectively to direction and speed of image motion in the rabbit

J. Physiol.

Principles of Optics

Ecology of the California ground squirrel on grazing land

Am. mid. Nat.

Retinoscopy and eye size

Science