visual system

• eyebrows - prevent perspiration from entering the eyes and helps shade the eyes
• eyelids- consists of 5 tissue layers
• conjunctiva - covers the inner eyelid and the anterior part of the eye
• lacrimal apparatus - produces tears, which flow across the surface of the eye
• tears- lubricate and protect the eye
• extrinsic eye muscle - moves the eyeball
• fibrous layer - includes the sclera & cornea
• sclera - maintains eye shape and provides attachment for muscles
• cornea - refracts light and contributes to focusing
• vascular layer - includes the choroid & iris
• choroid - supplies nutrients to the retina and prevents light scattering within the eye
• iris- regulates pupil size for light control
• retina - contains photoreceptors
• functions of the eye - refraction of light, accomodation, depth perception
• cornea - provides most refraction; lens - adjusts focus for near and far vision
• ciliary muscles - alter lens curvature for focusing on objects at different distances
• binocular vision and convergence - aid in perceiving depth and distance accurately
• retina is located at the back of the eye
• rods - responsible for non- color vision and night vision
• cones - responsible for color vision and visual acuity
• fovea centralis - high concentration of cones, crucial for detailed vision
• macula - contains more cones than rods, important for central vision
• primary visual cortex - processes basic information like orientation, motion, and spatial frequency
• dorsal stream (where pathway) - processes visual information related to motion, spatial location and object guidance for actions
• ventral stream (what pathway) - processes visual information related to object recognition, color, and form
• the component theory of color vision - human eye has three types of receptors
• the opponent-process theory - colors perceived in relation to each other in ipponent pairs
• the color constancy - perceived color of an object remains constant under varying illumination conditions
• evolutionary perspective - aid in object detection in natural environments