Flashcards
2. Eye & Retina
Cards in this deck (38)
- 1how do we go from the distal stimulus to the proximal stimulus with visual perception?light
- 2what is light?a form of electromagnetic energy & travels as a wave
- 3what is a wavelength & intensity?wavelength: peak to peak
intensity: peak to trough - 4how do we psychologically experience wavelengths & intensity?wavelength is perceived as colour, intensity is perceived as brightness
- 5what is the measurement/units of the position of wavelengths we're sensitive to?? i.e. visible light400 nm - 700 nm
- 6what are the colours for short, middle & long wavelengths?short: violets & blues
middle: greens & yellow
long: reds - 7how does light help us perceive the distal stimulus? (proximal stimulus)light that is emitted from a light source, scatters into the environment, is reflected from from objects
- 8what is the function of the eye?to produce in-focus images to the receptor cells
- 9where are receptor cells located? what're they called? (specialisation)in the retina -- photoreceptors
- 10Which parts of the eye form an edjustable aperture?Iris & pupil
- 11what are the iris & pupil?iris: coloured bit of eye
pupil: black hole in the middle - 12what does the pupil allow for?light to pass thru the eye to the receptor cells
- 13what is an adjustable aperture?where the iris & pupil work together to control & change the size of the pupil to change -- limiting or increasing -- the amount of light that ca pass thru
- 14what role do the cornea and the lens have? Where are they located?bending & focusing light to form an in-focus image onto the retina
Cornea - front most layer
Lens - right behind pupil - 15what is the focusing power of the cornea & lens?cornea: 80%
lens: 20% - 16which of the cornea & lens can change size? Why?Lens -- controlled by the ciliary muscles
- 17what is the process of the lens' changing shape due to the ciliary muscles?accomodation
- 18what are the effects of the lens being fatter & thinner?fatter = close objects focused (focusing point reaches closer instead of beyond)
thinner = far objects focused (focusing point reaches farther) - 19Name the two refractive errors & what they meanmyopia - nearsightedness, focus point is too short before it reaches the retina
hyperopia - farsightedness, focus point is beyond retina - 20which glasses & lens' shape can fix myopia & hyperopia?concave - myopia, bends light less, focus point travels further
Convex - hyperopia, bends light more, focus points gets shorter & closer - 21how is light being not so properly bent with each refractive error?myopia - light bent too much, doesn't reach retina
hyperopia - light bent too little, goes beyond retina - 22what is the retina? what is it composed of?photosensitive layer at the back of the eyeball, composed of multiple layers of diff. cells & neurons
- 23what are photoreceptors? what do they contain?light-sensitive receptors that carry out transduction, contain photopigments
- 24the two types of photoreceptorscone & rod
- 25which photoreceptor is best at night?rod
- 26which photoreceptor perceives colour?cones
- 27which photoreceptor is responsible for the purkinje shift? what is it?rod cells as they're monochromatic - red is a darker shade of grey than green
- 28which wavelength are rod cells most sensitive to?middle, green ones
- 29what are the 3 types of cone cells?red, green and blue
- 30what is the fovea?a small central area of the retina, right behind the pupil, which is densely packed with cone cells and has around 150k cells per millimetre squared
- 31what is dark adaptaion?where our eyes recover & regain their sensitivity to light when going into a dark place after being in a bright place
- 32after 20-30mins in the dark, how much reater is our light sensitivity?x100k
- 33what effect does very bright light have on our photopigets?bleaching effect
- 34what is convergence? which photoreceptor has more of it?where one neuron receives signals from many others -- rod cells
- 35on average, one ganglion cell receives signals from...120 rods, 6 cones
- 36what is acuity & what is it dependant on?acuity is the ability to detect fine details of a stimulus -- and is determined by neural convergence
- 37The greater the neural convergence..the lower the acuity
- 38which photoreceptor has higher acuity?cone cells -- as they have lower
neural convergence
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- Psychology (Intro to Sensation & Perception) Flashcards on 2. Eye & Retina, created by Reeth G on 14/05/2024.
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