Deck 2: Light and the Eyes

Question 1

The inner nuclear layer of the retina contains bipolar cells, horizontal cells, and:

A) amacrine cells.
B) retinal ganglion cells.
C) photoreceptors.
D) paracrine cells.

Answer 1

A

Question 2

A transparent membrane at the front of the eye is the:

A) retina.
B) cornea.
C) choroid.
D) iris.

Answer 2

B

Question 3

The _____ is an imaginary diameter line from the front to the back of the eye, passing through the center of the lens.

A) cornea
B) optic axis
C) choroid
D) lateral rectus

Answer 3

B

Question 4

The process of focusing light on the retina is performed by the cornea and the:

A) lens.
B) iris.
C) pupil.
D) anterior chamber.

Question 5

The superior and inferior rectus muscles move the eye:

A) up and down.
B) side to side.
C) clockwise and counterclockwise.
D) in all directions.

Question 6

The intraocular pressure in the three chambers of the eye is _____ the air pressure.

A) less than
B) equal to
C) greater than
D) unrelated to

Question 7

A strong lens has a relatively _____ focal length and a _____ angle of refraction.

A) long; small
B) short; large
C) long; large
D) short; small

Question 8

The only type of electromagnetic radiation that can be seen by the human eye is:

A) microwaves.
B) X-rays.
C) light.
D) ultraviolet rays.

Question 9

The _____ is the portion of the surrounding space that one can see when one's eyes are in a given position in their sockets.

A) choroid
B) field of view
C) retinal image
D) fovea

Question 10

Which statement about an optic array is FALSE?

A) It is the spatial pattern of brightness and color entering the eyes.
B) Moving objects in the environment will change the optic array.
C) It is constant and does not vary in space and time.
D) Changes in the lighting conditions can change the optic array.

Question 11

The extraocular muscles:

A) enable rapid and accurate eye movements.
B) control the size of the pupil.
C) control the shape of the lens.
D) supply the inside of the eye with oxygen and nutrients.

Question 12

Both the anterior and posterior chambers of the eye are filled with a clear thin fluid known as the:

A) retinal fluid.
B) vitreous humor.
C) aqueous humor.
D) chamber fluid.

Question 13

The _____ is the colored part of the eye, and the visible portion of the _____ is the white of the eye.

A) lens; pupil
B) cornea; sclera
C) iris; sclera
D) sclera; iris

Question 14

The surface of the retina can be seen through a(n):

A) tonometer.
B) ophthalmoscope.
C) imaging camera.
D) loupe.

Question 15

Photons that cross a boundary between two transparent or translucent media at an oblique angle are:

A) transmitted.
B) absorbed.
C) reflected.
D) refracted.

Question 16

A light source emitting a wavelength of approximately 700 nm would be perceived as:

A) dark red.
B) orange.
C) yellow.
D) green.

Question 17

Accommodation is the term used for the ability of the:

A) cornea to refract light.
B) pupil to change its size under different light conditions.
C) lens to adjust its shape to focus on objects at different distances from the eye.
D) retina to adjust its shape in response to bright light.

Question 18

A single particle of light is known as a(n):

A) neutron.
B) photon.
C) proton.
D) electron.

Question 19

Which statement is TRUE regarding the pupil of the eye?

A) It lets more light into the eye when it constricts.
B) It is an opening in the middle of the cornea.
C) The pupil of the left eye constricts when light is shone in the right eye.
D) The size of the pupil is controlled by the sclera of the eye.

Question 20

The three layers of membranes in the eye (from outer to inner) are:

A) the sclera, the retina, and the choroid.
B) the retina, the sclera, and the choroid.
C) the choroid, the retina, and the sclera.
D) the sclera, the choroid, and the retina.

Question 21

The photopigment in _____ is MOST sensitive to short-wavelength light, with a peak sensitivity at 443 nm.

A) rods
B) S-cones
C) M-cones
D) L-cones

Question 22

The area of the retina that does NOT contain any photoreceptors is the:

A) fovea.
B) macula.
C) optic disk.
D) outer segment.

Question 23

_____ receive signals from and send signals to horizontal cells in the retina.

A) Photoreceptors
B) Oblique muscles
C) Amacrine cells
D) Extraocular muscles

Question 24

The "business ends" of the photoreceptors, where transduction occurs, are embedded in a layer of cells called the:

A) outer nuclear layer.
B) pigment epithelium.
C) ganglion cell layer.
D) inner synaptic layer.

Question 25

The all-trans retinal and 11-cis-retinal shapes of photopigment molecules are known as:

A) phosphenes.
B) isomers.
C) photochromes.
D) enantiomers.

Question 26

In rod monochromats, the:

A) retina develops with cones but without rods.
B) optic disk consists only of cones.
C) retina develops with rods but without cones.
D) optic disk consists only of rods.

Question 27

The photopigments in _____ and _____ have some sensitivity across nearly the entire spectrum of visible light.

A) rods; M-cones
B) S-cones; L-cones
C) M-cones; L-cones
D) S-cones; rods

Question 28

The density of rods:

A) is highest in the optic disk.
B) remains constant throughout the retina.
C) rises rapidly within a short distance of the fovea.
D) is highest in the fovea.

Question 29

The layer of the retina CLOSEST to the vitreous chamber of the eye is the _____ layer.

A) inner synaptic
B) outer synaptic
C) outer nuclear
D) ganglion cell

Question 30

The density of cones:

A) is highest in the optic disk.
B) remains constant throughout the retina.
C) rises rapidly within a short distance of the fovea.
D) is highest in the fovea.

Question 31

The cones-only curve in a dark adaptation experiment is obtained by:

A) having a person suffering from glaucoma as the participant.
B) ensuring the spot of light falls only on the fovea.
C) ensuring the spot of light is away from the fovea.
D) having a rod monochromat as the participant.

Question 32

The process of photopigment regeneration:

A) is longer for cones than for rods.
B) is longer for rods than for cones.
C) aids in adjusting the operating range of the visual system.
D) causes the pigment molecules to resume the 11-trans shape.

Question 33

Which cells in the retina send action potentials to the brain via the optic nerve?

A) bipolar cells
B) amacrine cells
C) retinal ganglion cells
D) photoreceptors

Question 34

Photopigment regeneration:

A) occurs only in rod monochromats.
B) allows photopigment molecules to resume their 11-cis shape from all-trans.
C) is a property of retinal circuits with convergence.
D) compensates for the lack of photoreceptors in the optic disk.

Question 35

_____ is a property of retinal circuits with convergence in which signals from photoreceptors in some small space on the retina add up to affect the response of the retinal ganglion cells in the circuit.

A) Lateral inhibition
B) Accommodation
C) Photoisomerization
D) Spatial summation

Question 36

The degree to which a photopigment molecule absorbs light of different wavelengths is known as:

A) pupillary reflex.
B) visual acuity.
C) spectral sensitivity.
D) accommodation.

Question 37

_____ are capable of transducing light into neural signals in the retina.

A) Photoreceptors
B) Extraocular muscles
C) Horizontal cells
D) Oblique muscles

Question 38

How many different kinds of photopigment molecules are present in the human retina?

A) two
B) three
C) four
D) five

Question 39

The higher the degree of convergence in neural circuits:

A) the higher the number of one-to-one pattern of RGC and photoreceptor connections.
B) the lower the response to dim light.
C) the more the circuit supports visual acuity.
D) the more the circuit supports sensitivity to dim light.

Question 40

The _____ is the region of a sensory surface that, when stimulated, causes a change in the firing rate of a neuron.

A) fovea
B) blind spot
C) receptive field
D) near point

Question 41

The enhancement of edges in Mach bands can be explained by:

A) lateral inhibition.
B) convergence.
C) dark adaptation.
D) spatial summation.

Question 42

Which statement is FALSE with regard to cataracts?

A) They can result from an exposure to ultraviolet radiation.
B) They can be treated with a replacement lens that has a variable focal length.
C) They can be treated through surgery.
D) They can be a side effect of diabetes or other diseases.

Question 43

According to the text, in hyperopia:

A) the curvature of the cornea or the lens is slightly irregular or asymmetrical.
B) there is a progressive increase in the distance from the eye to the near point as the person ages.
C) a person can see distant objects clearly but not nearby objects.
D) a person can see nearby objects clearly but not distant objects.

Question 44

_____ refers to those signals sent by horizontal cells that tend to decrease the responses of photoreceptors in the center of the receptive field.

A) Lateral inhibition
B) Convergence
C) Edge enhancement
D) Spatial summation

Question 45

Light is described as having both wave-like and particle-like properties. Name one aspect of vision where light behaves as a particle and a different aspect of vision where light behaves as a wave.

Question 46

Night-vision devices based on thermal imaging convert the _____ emitted by the objects and surfaces in the scene into a visible electronic image.

A) infrared radiation
B) X-rays
C) phosphorescent light
D) ultraviolet light

Question 47

A disorder of the extraocular muscles in which the two eyes are not aligned with one another is called:

A) presbyopia.
B) astigmatism.
C) myopia.
D) strabismus.

Question 48

Define accommodation. Explain the process of accommodation occurring in the eye lens when focusing on objects at different distances from the eye.

Question 49

Which condition is characterized by a loss of vision due to damage to the photoreceptors in a region at the center of the retina?

A) macular degeneration
B) cataracts
C) retinitis pigmentosa
D) phosphenes

Question 50

Compare the focusing mechanism of an eye with that of a camera: Contrast their similarities and differences.

Question 51

In order to maximally stimulate a retinal ganglion cell with an on-center receptive field, a spot of bright light should strike:

A) both the center and the surround of the entire receptive field.
B) the entire center of the receptive field without touching the surround.
C) only the surround of the receptive field.
D) neither the center nor the surround of the receptive field.

Question 52

Which disorder of vision results from the intraocular pressure being too HIGH for a person's eye?

A) astigmatism
B) cataracts
C) glaucoma
D) floaters

Question 53

Which statement is TRUE regarding the disorders of accommodation?

A) Astigmatism cannot be corrected with glasses as opposed to other disorders of accommodation.
B) Presbyopia is characterized by a progressive decrease in the distance from the eye to the near point as the person ages.
C) Myopia and hyperopia cannot be detected until much later in life.
D) Myopia is known as nearsightedness, while hyperopia refers to farsightedness.

Question 54

Presbyopia is characterized by a:

A) progressive decrease in the distance from the eye to the near point as the person ages.
B) progressive increase in the distance from the eye to the near point as the person ages.
C) slightly irregular or asymmetrical cornea or lens, making complete accommodation impossible.
D) person being able to view nearby objects clearly but not distant objects.

Question 55

Figure 2.3 of the text is an illustration of the optic array and how it changes as the perceiver moves. In the first scene, the woman is sitting in a chair and can see part of her own lap, part of the red rug in front of the table (but not the part directly behind the table), most of the front legs of the table, and most of the lamp, except for the bottom of the base. When the woman stands up, the optic array changes; she can see part of the rug behind the table, less of the table legs, and the entire base of the lamp. What information about the scene is explicitly contained in the optic array? What information about the scene can only be inferred (or, not known directly) from the optic array?

Question 56

Which graph of Mach bands display does a person perceive when looking at the illustration below?

A) A
B) B

Question 57

Describe the path of a single photon from the time it enters the eye till the moment it is absorbed. Through which structures of the eye does the photon pass, and how is its path altered at each step?

Question 58

In which accommodation disorder does the optic axis become too long, resulting in the light coming to a focus in front of the retina?

A) myopia
B) hyperopia
C) astigmatism
D) presbyopia

Question 59

Which disorder of vision can be treated with LASIK surgery?

A) astigmatism
B) cataracts
C) glaucoma
D) floaters

Question 60

Studies on the midget versus parasol types of RGCs show that, at any given distance from the fovea:

A) both types of RGCs have similar receptive fields.
B) parasol RGCs have relatively small receptive fields and midget RGCs have relatively large receptive fields.
C) both types of RGCs send the same kind of visual information to the brain.
D) midget RGCs have relatively small receptive fields and parasol RGCs have relatively large receptive fields.

Question 61

A local police force is trying to decide which type of night-vision device (NVD) should be purchased for the squad. Describe the arguments that might be put forth by a salesman (assume there is a difference salesman for each device type) to promote their particular technology. Contrast thermal imaging and image enhancement in the answer.

Question 62

Why is there often a trade-off between acuity and sensitivity in the responses of retinal ganglion cells? Why do retinal ganglion cells that exhibit high acuity also tend to have relatively low sensitivity to light and vice versa?

Question 63

Should a person with mild presbyopia borrow glasses from a friend with myopia or one who has hyperopia? Support your answer with relevant arguments.

Question 64

A complex web of connections (which include the amacrine cells, the horizontal cells, and the bipolar cells) extends from the photoreceptors to the retinal ganglion cells. What is the advantage gained by the visual system from this complex processing, rather than simply propagating (or passing forward) the basic signal initially transmitted from each photoreceptor?

Question 65

Why is it so difficult to see both (a) when you first enter a darkened theater from a sunlit street, and (b) when you step out onto a sunlit street from a darkened theater?