Vision

Question 1

Visible light, or the energy we can see, is one form of __________
produced by the sun.

Answer 1

electromagnetic radiation

Question 2

____________, or the distance between successive peaks of waves, is decoded by the
visual system either as color or as shades of gray.

Answer 2

Wavelength

Question 3

The ___________ of light waves refers to the height of each wave, which is translated by
the visual system as brightness.

Answer 3

amplitude

Question 4

_________ always travel at the same speed (the so-called speed of light), but they can vary
in the amount of energy they possess. It is this variation in energy levels among photons
that gives us waves with different wave- lengths and amplitudes.

Answer 4

Photons

Question 5

PROPERTIES OF ELECTROMAGNETIC WAVES

Answer 5

First, electro- magnetic energy is abundant in our universe.

Second, because electromagnetic energy travels very quickly, there is no
substantial delay between an event and an organism’s ability to see the
event.

Finally, electromagnetic energy travels in fairly straight lines, minimizing
the distortion of objects.

Question 6

________ refers to the range of all types
of electromagnetic radiation.

Answer 6

electromagnetic spectrum

Question 7

_________ is a form of energy that includes
visible light, radio waves, microwaves, infrared radiation,
ultraviolet radiation, X-rays, and gamma rays.

Answer 7

Electromagnetic radiation

Question 8

These have the longest wavelengths and are
used for radio communication, television broadcasting, and other wireless technologies.

Answer 8

Radio Waves

Question 9

Slightly shorter wavelengths than radio waves: are used in microwave ovens and for various forms of wireless communication, including cell phones and
Wi-Fi.

Answer 9

Microwaves

Question 10

______ is what we
perceive as heat. It’s used in night-vision technology and various industrial and scientific applications.

Answer 10

Infrared Radiation (IR)

Question 11

This is the part of the spectrum that
our eyes can detect. It includes all the colors of the rainbow, with each color corresponding to a different wavelength.

Answer 11

Visible Light

Question 12

_______ radiation has shorter
wavelengths than visible light and is responsible for causing
sunburn and skin damage. It’s also used in some sterilization
processes.

Answer 12

Ultraviolet (UV) Radiation

Question 13

_______ have the shortest
wavelengths and the highest energy. They are produced in
nuclear reactions and are used in medical treatments and
certain types of imaging.

Answer 13

Gamma Rays

Question 14

The clear, frontmost part of the eye that covers the iris and the pupil. It plays a significant role in focusing light onto the retina.

Answer 14

Cornea

Question 15

The colored part of the eye surrounding the pupil. It controls the size of the pupil and
regulates the amount of light entering the eye.

Answer 15

Iris

Question 16

The dark, central opening in the iris that changes in size to control the amount of light that
enters the eye. In bright conditions, it contracts (becomes smaller), and in dim conditions,
it dilates (becomes larger).

Answer 16

Pupil

Question 17

Located behind the iris, the lens helps to further focus light onto the retina. It can change
shape (accommodate) to allow for clear vision at different distances.

Answer 17

Lens

Question 18

The innermost layer at the back of the eye that contains photoreceptor cells (rods and
cones) responsible for detecting light and transmitting visual signals to the brain.

Answer 18

Retina

Question 19

The bundle of nerve fibers that carries visual information from the retina to the brain,
where it is processed and interpreted.

Answer 19

Optic Nerve

Question 20

The tough, white outer layer of the eye that provides protection and maintains the shape
of the eye. It covers most of the eyeball.

Answer 20

Sclera

Question 21

A clear, gel-like substance that fills the space between the lens and the retina. It helps
maintain the eye’s shape and provides some optical properties.

Answer 21

Vitreous humor

Question 22

The layer of blood vessels and connective tissue between the retina and the sclera. It
provides nutrients to the retina and absorbs excess light.

Answer 22

Chloroid

Question 23

A clear, watery fluid found in the front part of the eye, between the cornea and the lens. It
helps maintain the shape of the front of the eye and nourishes the cornea and lens.

Answer 23

Aqueous humor

Question 24

The retina’s first layer is the __________ Each has a single axon, and these axons form the optic nerve as it leaves the retina.

Answer 24

ganglion cell layer.

Question 25

In the _____________ the dendrites of ganglion cells form connections with the amacrine and bipolar cells.

Answer 25

inner plexiform layer,

Question 26

The __________ contains the cell bodies of the photoreceptors.

Answer 26

outer nuclear area

Question 27

The two types of photoreceptors, ____________, are named according to the shape of their outer segments

Answer 27

rods and cones

Question 28

The outer segment is the part of the photoreceptor that absorbs light. The outer segment contains ___________, chemicals that interact with incoming light.

Answer 28

photopigments

Question 29

The human eye contains about _________ million rods

Answer 29

120

Question 30

Rods are responsible for __________, or the ability to see in dim light.

Answer 30

scotopic vision

Question 31

There are only about ___ million cones in the human eye.

Answer 31

6

Question 32

Cones are responsible for ________, or vision in bright light.

Answer 32

photopic vision

Question 33

Rods are highly sensitive to low levels of light and are primarily responsible for vision in dim or low-light conditions. This makes them essential for night vision.

Answer 33

Sensitivity to Light Levels

Question 34

Rods contain a photopigment called ________, which is sensitive to a broad range of wavelengths, allowing them to detect different shades of gray.

Answer 34

rhodopsin

Question 35

Rods are mainly located in the _______ of the retina, which is why our peripheral vision is more sensitive to low-light conditions.

Answer 35

peripheral regions

Question 36

Rods do not contribute to color vision. They are monochromatic and cannot differentiate between colors.

Answer 36

Absence of Color Vision

Question 37

Cones are responsible for ________ and are highly sensitive to different wavelengths of light.

Answer 37

color vision

Question 38

THREE TYPE OF CONES

Answer 38

S-cones (blue), M-cones (green), and L-cones (red), each sensitive to a specific range of colors.

Question 39

Cones are concentrated in the central region of the retina, known as the ___________. This area provides the sharpest and most detailed vision and is essential for activities like reading and recognizing faces.

Answer 39

fovea

Question 40

Cones work best in well-lit or daylight conditions. They are responsible for high-resolution vision and the perception of fine details.

Answer 40

Daylight and Bright-Light Vision

Question 41

Cones are less sensitive to motion than rods and are more suited for stationary or slow-moving objects.

Answer 41

Limited Sensitivity to Motion

Question 42

_________ is the process of translating a physical stimulus into electrical signals that can be understood and processed by the nervous system.

Answer 42

Transduction

Question 43

The simplest patterns of lines are known as _________

Answer 43

gratings

Question 44

The human visual system could perform a rough mathematical analysis, or ___________, of the gratings found in the visual field

Answer 44

spatial frequency analysis

Question 45

primary colors of light

Answer 45

red, green, blue

Question 46

_____ theory suggests that human color vision is based on our having three (tri) different color photopigments. The three photopigments are maximally responsive to lights of different wavelengths.

Answer 46

Trichromacy

Question 47

Occasional errors occur in the chromosomes that carry the genes that encode the cone photopigments. As a result, individuals with these genes show several kinds of atypical responses to color, known as ____________.

Answer 47

colorblindness