. Elements of human physiology. Physiology. 552 PHYSIOLOaY 111 the eye there are several surfaces separating different media where refraction takes place (Fig. 244). Since the Fig. Section through eyeball to show refractive media. Sc. Sclerotic coat. Ch. Choroid coat. V. Vitreous humour. L. Lens. S. Suspen- sory ligament of lens. ON. Optic nerve. C. Cornea. Aqueous humour. Ir. Iris. refractive index of the aqueous humour is almost equal to that of the cornea, we may reduce the refracting surfaces to three, viz.— Anterior surface of cornea. Anterior surface of lens, Posterior surfac
. Elements of human physiology. Physiology. 552 PHYSIOLOaY 111 the eye there are several surfaces separating different media where refraction takes place (Fig. 244). Since the Fig. Section through eyeball to show refractive media. Sc. Sclerotic coat. Ch. Choroid coat. V. Vitreous humour. L. Lens. S. Suspen- sory ligament of lens. ON. Optic nerve. C. Cornea. Aqueous humour. Ir. Iris. refractive index of the aqueous humour is almost equal to that of the cornea, we may reduce the refracting surfaces to three, viz.— Anterior surface of cornea. Anterior surface of lens, Posterior surface of lens ; and the refracting media to three— Aqueous humom* (or cornea), Lens, Vitreous humour. These are so adapted in the normal eye that parallel rays falling on the cornea are converged to a focus at the yellow spot on the retina. This pomt therefore represents the principal focus of the eye. A line drawn from this point through the centre of the cornea is the optic axis of the eyeball. The Mechanism of Accommodation But we are able also to form a distinct image of near objects on the retina, and we notice that, when we turn our gaze from far to near objects, there is a distinct feeling of. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Starling, Ernest Henry, 1866-1927. Chicago : W. T. Keener
Size: 1953px × 1279px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectphysiology, bookyear1
