2. Volgograd State Medical University Department Normal Physiology Physiology Of Vision Rodion A. Kudrin

5. 1. Anatomy of the eye

7. Ciliary body Suspensory ligament Posterior cavity containing vitreous humor Ciliary muscle in ciliary body Posterior chamber Anterior chamber Anterior cavity Aqueous humor Iris Canal of Schlemm

11. Sympathetic stimulation Iris Cornea Flattened Weak lens Relaxed ciliary muscle Taut suspensory ligaments

13. Sclera Choroid Fovea Optic disc Lens Retina Pupil Iris

15. Sympathetic stimulation Rounded strong lens Contracted ciliary muscle Slackened suspensory ligaments

16. Suspensory ligaments Ciliary muscle Lens Pupillary opening in front of lens The iris is circular and pigmented. It is two layers of smooth muscle that control the amount of light passing through the pupil and into the eye.

26. 3. Accommodation of the eye for objects at different distances This diagram shows how light from afar is bent by the stretched lens to strike the retina, and how light from a closer source is bent even more sharply by the relaxed lens to strike the retina

37. Normal vision

40. Myopia

41. Myopia

43. Hypermetropia

44. Hypermetropia

47. Astigmatism

48. Astigmatism

58. 7. Photoreceptors

61. 8. Visual pathways

62. 8. Visual pathways This scheme shows the flow of information from the eyes to the central connections of the optic nerves and optic tracts, to the visual cortex. Area V1 is the region of the brain which is engaged in vision .