photoreceptors
Retinal light sensors
Photoreceptors are cells that detect light.
In the eye, rods and cones are the photoreceptors that convert light into electrical signals sent to the brain—rods handle low-light vision, cones handle color.
The term also applies to light-sensitive proteins in plants and microorganisms that trigger responses to light exposure.
Thin cylindrical shafts
- conesTapering geometric solids
- retinaLight-sensing tissue layer
- maculaRetinal region for acuity
- foveaRetinal depression for acuity
optic nerve · cilium · ellipsoid · pedicle · spherule
Light-absorbing retinal molecule
- retinalOf eye's inner lining
- chromophoreMolecule's tint-causing portion
- 11-cis-retinalOpsin-bound visual pigment
- isomerizationMolecular rearrangement keeping same atoms
Perceiving hue differences
- scotopicRelating to dim-light vision
- night visionAbility to see dimly
- visual acuityClarity of eyesight
- light sensitivityAdverse reaction to brightness
motion detection · peripheral vision · central vision · wavelength · luminance
Retinal disease causing central blindness
- night blindnessImpaired vision in darkness
- color blindnessInability to perceive hues
- retinal detachmentPhotoreceptor layer separates from eye
Excessive membrane voltage negativity
- depolarizationLoss of electrical gradient
- amplificationIncrease in intensity
- electrical signalInformation via current
- calcium influxIons flowing into cytoplasm
rods
Thin cylindrical shafts
fovea · optic nerve · cilium · ellipsoid · pedicle · spherule
photopigment
Light-absorbing retinal molecule
- retinalOf eye's inner lining
- chromophoreMolecule's tint-causing portion
- 11-cis-retinalOpsin-bound visual pigment
color vision
Perceiving hue differences
- scotopicRelating to dim-light vision
- night visionAbility to see dimly
- visual acuityClarity of eyesight
light sensitivity · motion detection · peripheral vision · central vision · wavelength · luminance
rod cells
Light-sensitive retinal neurons
macular degeneration
Retinal disease causing central blindness
- night blindnessImpaired vision in darkness
- color blindnessInability to perceive hues
- retinal detachmentPhotoreceptor layer separates from eye
hyperpolarization
Excessive membrane voltage negativity
- depolarizationLoss of electrical gradient
- amplificationIncrease in intensity
- electrical signalInformation via current
- visionsharp, eye, visual perception, sight, eyes
- cellscells, blood cell, cell theory, nerve cell, red blood cell
- sensessight, smell, taste, hearing, touch
- animal visioncat eyes, compound eyes, cornea, depth perception, eagle eye
- eye anatomyeyeball, cornea, iris, retina, pupil
- Light Biologyphotoreception, rod cells, retina, light sensitivity, optic nerve
photoreceptorsmechanoreceptors
Sensory cells detecting pressure
chemoreceptors · baroreceptors · proprioceptors · electroreceptors · pain receptors