1. Light, Optics, and Eyes Flashcards
Differences Between Tubes, Pinholes, and Lenses
Tubes: There are many tubes stacked next to each other and each tube receives input from one direction.
Pinholes: Light goes through the aperture and projects inverted images onto the surface.
Lens: Prism bends light to form an image
Why do we see objects?
Because objects reflect light. Light reflects in different directions
Angle of Incidence
Angle of Reflection
Differences between light that is transmitted, reflected, refracted, scattered, and absorbed
Transmitted: to convey light from one place to another; it is neither reflected or absorbed
Reflected: redirection of light that strikes a surface
Refracted: the bending of light
Cornea
Transparent window into the eyeball. Has the most focusing power.
Lenses (what is it used for and how many lenses do humans have?)
Transparent surface used for fine tuning; a structure inside the eye that enables the changing of focus.
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Fovea (what is it, what does it do, and where is it located)
Densely packed receptor with the highest concentration of cones; no rods
Produces the highest visual acuity and serves as the point of fixation
Located: near the center of the macula
Macula
Sheilds fovea from blue light
Where are cones most concentrated?
The Fovea
Do receptors exist in the blind spot?
No
Backward Retinal Wiring
Cornea, Lens, Pupil, Vitreous Humor, Retina (inner limiting membrane, ganglion cells, bipolar cells + Amacrine Cells + Horizontal Cells, Rods and Cones
What parts of the eye are activated in light vs dark settings
By daylight, only the central fovea sees clearly and in color
On dark nights, only the periphery sees, only in black and white
and with poor resolution. The fovea is blind.
Sensitivity vs Acuity/Resolution
Sensitivity = can detect dim lights
Acuity = can see (resolve) fine details
Differences between Cones and Rods
Cones: a photoreceptor with higher resolution, low sensitivity at center (daylight vision)
Rods: a photoreceptor with low resolution, high sensitivity in periphery (nightvision)
What are Photoreceptors?
Light sensitive receptor in the retina (Cones and Rods)
Do we have more rods or cones?
While our vision is dominated by cones, the number of rods far exceeds the number of cones
