> 6 MILLION > ARE COLOR SENSITIVE > FOUND MOSTLY IN FOVEA

> TRANSPARENT STRUCTURE SITUATED BEHIND THE PUPIL. > IT FOCUSES LIGHT ONTO THE RETINA AND PLAYS A KEY ROLE IN ADJUSTING THE EYE'S FOCUS

> IS A LIGHT-SENSITIVE MOLECULE THAT BINDS TO OPSINS. > WHEN BOUND TO OPSINS, ______ UNDERGOES A SERIES OF CHEMICAL REACTIONS THAT ALLOW THE OPSINS TO DETECT LIGHT AND TRANSMIT SIGNALS TO THE BRAIN

> first scientific theory of color vision > proposed by Hermann von Helmholtz > three types of cones sensitive to diff. wavelengths of light

> neurons have smaller cellular bodies > respond to color, fine details, still objects, slow moving objects

> as few as one per ganglion cell > low sensitivity, high aquity

interprets spatial information (location/motion)

> THE COLORED PART OF THE EYE THAT CONTROLS > THE SIZE OF THE PUPIL, THUS REGULATING THE AMOUNT OF LIGHT THAT ENTERS THE EYE

> ARE RESPONSIBLE FOR NIGHT VISION. > THEY DETECT CHANGES IN LIGHT INTENSITY AND SIGNAL THE BRAIN TO ADJUST THE PUPIL SIZE AND SENSITIVITY TO LIGHT

> ARE RESPONSIBLE FOR INTEGRATING AND MODULATING THE SIGNALS RECEIVED FROM THE PHOTORECEPTORS, THUS CONTRIBUTING TO THE INITIAL PROCESSING OF VISUAL INFORMATION WITHIN THE RETINA

THE NERVE THAT TRANSMITS VISUAL INFORMATION FROM THE RETINA TO THE BRAIN FOR FURTHER PROCESSING

> occurs when there is plenty of light > cones are responsible

THE FUNCTION OF A ________ IS TO DETECT ELECTROMAGNETIC RADIATION (EMR) EMITTED BY OBJECTS

> people organize sensations into meaningful whole > perceptions are naturally organized according to certain patterns

> RECEIVE INPUT FROM THE BIPOLAR CELLS AND TRANSMIT IT TO THE BRAIN VIA THE OPTIC NERVE. > THERE ARE TWO TYPES:ON&OFF * ON ARE EXCITED BY LIGHT * OFF ARE INHIBITED BY LIGHT

> 120 MILLION > LIGHT SENSITIVE (NOT COLOR) > FOUND IN PERIPHERY OF RETINA > LOW ACTIVATION THRESHOLD

form or whole in German

> ARE RESPONSIBLE FOR COLOR VISION AND VISUAL ACUITY

> THE OPENING IN THE CENTER OF THE IRIS, WHICH GIVES OUR EYES THEIR COLOR. > ITS PRIMARY FUNCTION IS TO ALLOW LIGHT TO ENTER THE EYE SO IT CAN BE FOCUSED ON THE RETINA TO BEGIN THE PROCESS OF SIGHT

opsin

> ARE SPECIALIZED NERVE CELLS THAT TRANSDUCE ENERGY INTO NEURAL SIGNALS

> PROPOSES THAT ONE MEMBER OF THE COLOR PAIR SUPPRESSES THE OTHER COLOR. > PROPOSED BY GERMAN PHYSIOLOGIST EWALD HERING IN THE LATE 1800S.

> IS A SMALL, HIGHLY SPECIALIZED AREA OF THE RETINA THAT IS RESPONSIBLE FOR OUR CENTRAL VISION > PROVIDES THE SHARPEST VISUAL ACUITY NEEDED FOR DETAILED TASKS LIKE READING AND DISTINGUISHING BETWEEN DIFFERENT COLORS.

the perpetual tendency to organize stimuli into meaningful groups

> ARE RESPONSIBLE FOR VISION IN LOW LIGHT CONDITIONS

> DENSELY PACKED WITH PHOTORECEPTORS, PARTICULARLY CONES, WHICH ARE RESPONSIBLE FOR COLOR VISION. > IT IS OFTEN COMPARED TO THE BULLSEYE ON A DARTBOARD, EMPHASIZING ITS CRITICAL ROLE IN OUR ABILITY TO SEE FIN E DETAILS AND PERCEIVE COLOR.

> LIGHT SPLITS THE OPSIN AND RETINAL APART >ACTIVATES TRANSDUCIN (G PROTEIN)-> > ACTIVATES PHOSPHODIESTERASE-> >REDUCES CGMP -> CLOSES NA+ CHANNELS

gaps of myelin sheath

happens when visual stimulis are presented at different locations in a sequential manner

SIGNALS FROM THE GANGLION CELLS OF THE RETINA ARE SENT TO THE _______ VIA THE OPTIC NERVE/TRACT

organization of visual field into objects that stand out from their surroundings

> organizing and interpreting visual signals

> ARE RESPONSIBLE FOR COLOR VISION. > THERE ARE THREE TYPES OF THESE OPSINS IN HUMANS: SHORT-WAVELENGTH, MIDDLE-WAVELENGTH, AND LONG-WAVELENGTH OPSINS * EACH RESPONSIBLE FOR DETECTING A SPECIFIC RANGE OF LIGHT WAVELENGTHS

retinal

THE RETINA CONSISTS OF THREE LAYERS OF CELLS > RECEPTORS IN THIS LAYER TRANSDUCE LIGHT

> ARE LOCATED IN THE MEMBRANE OF THE OUTER SEGMENT OF RODS AND CONES

> is the sensory organ used for vision > detect light and send signals to the brain, which then interprets these signals to create the visual experience.

HUMANS CAN DETECT LIGHT WITH A WAVELENGTH BETWEEN

fastening of action potential

IS RELATED TO THE WAVELENGTH OF LIGHT BRIGHTNESS IS RELATED TO THE INTENSITY OF THE RADIATION

> THE CLEAR, DOME-SHAPED SURFACE THAT COVERS THE FRONT OF THE EYE. IT IS RESPONSIBLE FOR REFRACTING LIGHT AND PLAYS A CRUCIAL ROLE IN FOCUSING LIGHT RAYS ONTO THE RETINA

> ARE SPECIALIZED CELLS THAT DETECT LIGHT AND CONVERT IT INTO ELECTRICAL SIGNALS. > THERE ARE TWO TYPES: RODS AND CONES

> IN THE DARK, MEMBRANE NA+ CHANNELS ARE OPEN >GLUTAMATE IS RELEASED

> hundreds per ganglion cell > can amplify a dim light source > high sensitivity, low aquity

> LIGHT-SENSITIVE LAYER THAT LINES THE INTERIOR OF THE EYE. > IT CONTAINS PHOTORECEPTOR CELLS CALLED RODS AND CONES, WHICH CONVERT LIGHT INTO NEURAL SIGNALS

> is responsible for transmitting visual information from the optic nerves to the occipital lobes of the brain

THE ___________ OF A ROD OR A CONE CONTAINS DIFFERENT PHOTOPIGMENTS THAT REACT TO LIGHT

> THE TOUGH, WHITE OUTER LAYER OF THE EYEBALL, PROVIDING IT WITH STRUCTURAL SUPPORT AND PROTECTION

> dim light > rods are responsible

interprets object characteristics (color/shape)

> ability to see objects in 3D > although images that strike the retina are 2D > allows people to judge distance