Anatomy and physiology : designed for academies and families . es of convexity or concavity also modifythe refracting character of transparent media. The crystallinelens is of different degrees of convexity on its two convex surfaces of the ar?eous and vitreous humors are I What is the effect, when there is s vbsence of the paint on the choroidcoat? Why are optical instruments, olored black on the interior surface?What is the function of the iris ? What is the character of the humors of theeye? What is the office of the cornea and humors? What is said of thedensity of the crystalline
Anatomy and physiology : designed for academies and families . es of convexity or concavity also modifythe refracting character of transparent media. The crystallinelens is of different degrees of convexity on its two convex surfaces of the ar?eous and vitreous humors are I What is the effect, when there is s vbsence of the paint on the choroidcoat? Why are optical instruments, olored black on the interior surface?What is the function of the iris ? What is the character of the humors of theeye? What is the office of the cornea and humors? What is said of thedensity of the crystalline lens ? What kind of lenses do the various humorsexhibit ? What modifies the refracting powers of lenses ? PHYSIOLOGY OF THE EYE. 277 segments of circles, of different diameters from their concavesurfaces. See Fig. 190. All these circumstances still furtherinfluence the refracting character of the visual organ. Theachromatic arrangement of the transparent refracting mediaof the eye, remedies the aberration of refraction in the differ-ent portions of the Fig. 191. Represents the forms of the different lenses. 1, A plane lens. 2, A globelens. 3, A convexo-convex lens. 4, A plano-convex lens. 6, A concavo-concaveleus. 6, A plano-concave lens. 7, Meniscus. 8, A concavo-convex lens. Again, the refracting power of lenses is modified by theirconvexity or concavity. The more convex a lens is, theshorter the distance from the refracting medium, when thedifferent refracted rays converge to a focus. To adapt theeye to view objects at different distances requires a change inthe refracting power of some of the transparent media of theeye. Both surfaces of the crystalline lens are oval, not spheri-cal, and the refraction of the rays of light is mainly effectedin this portion of the eye. Change the inclination of this lens,so that different portions of its anterior surface shall be direct-ly behind the pupil, and its refracting power is increased ordiminished, as the surface presented i
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectanatomy, bookyear1847
