Elements of Seeing ( mura namag bio atay) Flashcards
The ___________ of a human is composed of the eye, optic nerve, and certain parts of the brain.
visual system
The _______ is the organ that allows a human to ______ light and produces electrical ______ that will be sent through the optic nerve to the brain.
eye, sense, impulses
The ________ is that part of the visual system where impulses are ____________.
brain, processed
Rays of light pass through the transparent _________ of the eye and through an opening called the ____________.
cornea, pupil
The ______ surrounds the pupil and adjusts for the amount of light available. It ______ and _________ to control the __________ of light the interior of the eye receives.
iris, opens, closes, quantity
The ________ is a transaprent ellipsoidal medium that changes ___________, allowing it to ________ and _____________ the rays of light entering the interior of the eye.
lens, thickness, bend and focus,
The lens concentrates the rays of light on the ______________, a membrance on the back of the eye.
retina
LENS
thickens: ________
narrows: _____________
nearby
distant
The ___________ is composed of nerve cells with _____________ that are shaped like ________ and ___________.
retina, photoreceptors, cones, rods
The photoreceptors that are shaped like _________ provide color vision and respond best to ________ light.
cones, bright
There are three types of cone-shaped photorecepors in the retina, each of the type responds to one ___________ colors of light. which are ______,____,___.
primary, green, blue, red.
About __% of the population, mostly males, has defective color vision.
5%
It is the inability to distinguish colors. commonly _________ and _________.
color blindess, red, green
People who are completely red-green colorblind tend to see red and greens as __________.
yellow
Light is a form of energy known as ___________________.
electromagnetic radiation
Light travels as an ______________.
electromagnetic wave
Unlike sound, light travels through __________ of space - unlike sound.
vacuum
Ligh travels for __________ km/s.
300,000
It is an energy radiated in the form of a wave caused by an electric field interacting with a _____________.
Electromagnetic Radiation, magnetic field
It results in the acceleration of charged particles
Electromagnetic Radiation
Electromagnetic radiation is categorized by _____________ and ____________.
wavelength , frequency
meassures as a distance from one peak of one wave to the next wave.
wavelength
wavelength is expressed in ________ or _____________
meters, nanometers ( 1 nm is 000 001 meter or one billionth of a meter)
Frequency is the number of waves per second expressed in units of ________.
hertz
Most light sources emit electromagnetic radiation composed of different ___________ of light.
UV - ____%
Visible light - ____%
infrared radiation- ____ %
wavelengths
5
45
50
It is a part of electromagnetic spectrum and capable of exciting the retina and ultimately producing visual sensation
Visible light
It is the wavelengths of electromagnetic radiation to which the human eye is sensitive
visible light
When light strikes a surface, the surface is ___________.
illuminated
It is the amount of light incedent on ( striking) of a surface.
Illuminance
It is how bright an object appears
Luminance
The eyes sees_________ as the light leaving the object, but the eye cannot see it without ________________ reflecting off the object in the direction of the ____________.
luminance, visible light, viewer
It is the ratio of the reflected light versus the light striking the surface.
Reflectance
It is the ratio of light transmitted through body to light illuminating surface. A _______ body transmits light without distorting the image.
Transmittance, transparent
It is the ratio of the light absorbed versus the light striking the surface.
Absorptance
