Deck 2: Light and the Eyes

Question 1

The extraocular muscles

A)control eye movements.
B)control the size of the pupil.
C)control the shape of the lens.

Answer 1

A

Question 2

Accommodation is the term used for the

A)ability of the cornea to refract light.
B)changing of the size of the pupil under different light conditions.
C)changing of the shape of the lens to focus light on the retina.

Answer 2

C

Question 3

The only type of electromagnetic radiation that humans can see is

A)microwave radiation.
B)X-rays.
C)between about 370 nm to about 730 nm.

Answer 3

C

Question 4

The eyes of most prey animals are positioned

A)in the front of the head.
B)on the sides of the head.
C)to provide high-resolution depth perception.

Question 5

______________ are found in the retina and send signals to bipolar,amacrine,and retinal gan- glion cells.

A)Bipolar cells
B)Amacrine cells
C)Both bipolar and amacrine cells

Question 6

The cornea is the transparent portion of the

A)retina.
B)sclera.
C)choroid.

Question 7

When the pupil ,it allows light into the eye.

A)constricts;more
B)dilates;less
C)constricts;less

Question 8

Which of the following receive signals from horizontal cells?

A)photoreceptors
B)bipolar cells
C)amacrine cells

Question 9

The inner nuclear layer of the retina contains

A)bipolar,horizontal,and amacrine cells.
B)bipolar,horizontal,and retinal ganglion cells.
C)photoreceptors,horizontal cells,and amacrine cells.

Question 10

The makes up the colored part of the eye while the makes up the white of the eye.

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

Question 11

A strong lens

A)has a relatively long focal length.
B)has a relatively short focal length.
C)has a relatively small angle of refraction.

Question 12

The focusing of light onto the surface of the retina is due to the lens and the

A)cornea.
B)iris.
C)pupil.

Question 13

The field of view (i.e. ,that portion of the surrounding space that you can see when your eyes are in a given position in their sockets)

A)is greater for humans than it is for crocodiles.
B)is greater for crocodiles than it is for humans.
C)is about 360 degrees horizontally for humans.

Question 14

An ophthalmologist uses a to examine the retina.

A)tonometer
B)ophthalmoscope
C)thermal imaging camera

Question 15

The largest of the three fluid-filled chambers in the eye is the

A)anterior chamber.
B)posterior chamber.
C)vitreous chamber.

Question 16

A single particle of light is called a

A)neutron.
B)photon.
C)wavelength.

Question 17

The optic axis includes

A)the fovea.
B)the optic disk.
C)the zonule fibers.

Question 18

A light source with a wavelength of approximately 700 nm would be perceived as the color

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

Question 19

The superior and inferior rectus muscles move the eyes

A)up and down.
B)side to side.
C)counterclockwise and clockwise.

Question 20

The purpose of intraocular pressure is

A)to keep the lens and cornea separated.
B)to enhance the vivid colors of the iris.
C)to maintain the spherical shape of the eye.

Question 21

When 11-cis retinal absorbs light it changes into ,which results in a(n)in the amount of neurotransmitter released by the photoreceptor.

A)all-trans retinal;increase
B)all-trans retinal;decrease
C)12-cis retinal;decrease

Question 22

Myopia is due to while presbyopia is due to .

A)an optic axis that is too short;an optic axis that is too long
B)an optic axis that is too long;an optic axis that is too short
C)an optic axis that is too short;a lens that is no longer elastic enough to focus near objects

Question 23

In a center-surround receptive field,lateral inhibition

A)is due to inhibitory signals sent from one photoreceptor to an adjacent photoreceptor.
B)is due to inhibitory signals sent from horizontal cells to photoreceptors.
C)is due to inhibitory signals sent from photoreceptors to horizontal cells.

Question 24

The area of the retina that contains no photoreceptors is the

A)fovea.
B)macula.
C)optic disk.

Question 25

Highly convergent neural circuits are found

A)mostly in the fovea.
B)mostly in the periphery of the retina.
C)equally distributed in the fovea and the periphery.

Question 26

______________ results from the optic axis being too long and light being focused in front of the retina.

A)Myopia
B)Hyperopia
C)Amblyopia

Question 27

Cone photoreceptor density is greatest

A)at the optic disk.
B)in the fovea.
C)about 8 mm from the fovea.

Question 28

Photopigment regeneration

A)takes longer for cones than for rods.
B)takes longer for rods than for cones.
C)takes the same amount of time regardless of photoreceptor type.

Question 29

In order to maximally stimulate a RGC with an on-center receptive field,the light should

A)strike the entire receptive field.
B)strike all of the center of the receptive field and none of the surround of the receptive field.
C)strike only the surround of the receptive field.

Question 30

______________ transduce light into neural signals.

A)Photoreceptors
B)Bipolar cells
C)Retinal ganglion cells

Question 31

Rod monochromats

A)have very good visual acuity.
B)see much better in daylight conditions than at night.
C)produce dark adaptation curves without the characteristic rod-cone break.

Question 32

The enhancement of edges in Mach bands can be explained by

A)lateral inhibition.
B)the activity of rods but not cones.
C)dark adaptation.

Question 33

Photopigment regeneration occurs during

A)light adaptation.
B)dark adaptation.
C)light adaptation for rods and dark adaptation for cones.

Question 34

In order to establish a dark adaptation curve for cone photoreceptors,the test light that the par- ticipant adjusts would be

A)shown away from the fovea.
B)shown directly on the fovea.
C)shown to both the foveal and peripheral regions of the retina.

Question 35

Rods while cones .

A)support daylight vision;support night vision
B)number about 100 million in each eye;number about 5 million in each eye
C)dark-adapt quickly;dark-adapt slowly

Question 36

The position of the near point

A)gets increasingly closer from the eye with age.
B)gets increasingly farther from the eye with age.
C)has not been shown to be related to age.

Question 37

The size of the receptive field for each RGC is

A)100:1.
B)differs depending upon its position in the retina.
C)1000:1.

Question 38

Which retinal cells are capable of transduction?

A)photoreceptors
B)bipolar cells
C)horizontal cells

Question 39

The minimal amount of light that a rod can respond to is

A)1 photon.
B)10 photons.
C)100 photons.

Question 40

The outer segment ("business end")of the photoreceptors

A)synapses with the bipolar cells.
B)is embedded in the pigment epithelium.
C)is part of the outer nuclear layer.

Question 41

______________ is characterized by a loss of vision in the area of the fovea,while results in the opposite (i.e. ,tunnel vision).

A)macular degeneration;retinitis pigmentosa
B)cataracts;macular degeneration
C)retinitis pigmentosa;macular degeneration

Question 42

Which of the following constitutes part of the retina's through pathway?

A)bipolar cells
B)amacrine cells
C)horizontal cells

Question 43

When viewing an object at close distance,the lens becomes and the ciliary muscles are .

A)thinner;relaxed
B)thinner;contracted
C)thicker;relaxed

Question 44

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

Question 45

Light is described as having a wave-particle duality.Explain one aspect of vision for which you must refer to light as a particle and a different aspect of vision for which you must refer to light as a wave.

Question 46

Light differs from other forms of electromagnetic radiation in that

A)light behaves like a wave.
B)light is composed of a stream of particles.
C)we can see it.

Question 47

In a pinch,should a person with mild presbyopia borrow glasses from their friend with myopia or hyperopia? Of course,it is not recommended that you borrow anyone's glasses,but for which visual disorder would the prescriptive correction be more similar to that for presbyopia?

Question 48

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

Question 49

The optic disk is also known as the

A)choroid.
B)pigment epithelium.
C)blind spot.

Question 50

Starting at the center of fixation and working your way out to the visual periphery,describe the changes that occur in (a)visual acuity, (b)sensitivity to light,and (c)color discrimination.

Question 51

Compare the focusing mechanism of the eye to that of a camera: How are they similar? How are they different?

Question 52

The dark-adaptation curve indicates that after about 5 to 7 minutes in the dark

A)the eyes are fully dark-adapted.
B)most rods have completed photopigment regeneration.
C)cones have reached their maximum sensitivity.

Question 53

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

Question 54

______________ is the name for a disorder of vision in which the intraocular pressure is too high.

A)Astigmatism
B)Cataracts
C)Glaucoma

Question 55

The pupillary reflex is a(n)

A)change in the opening of the iris in response to a change in light intensity.
B)when the eye is automatically directed toward motion in the visual scene.
C)adjustment in the thickness of the lens in response to a change in light intensity.

Question 56

Compared to animals with eyes on the sides of their heads (such as crocodiles),animals with eyes in front (such as humans)

A)are better able to detect the presence of prey.
B)have a wider range of high-resolution depth perception.
C)have a much more extensive field of view.

Question 57

Night-vision devices based on thermal imaging are most sensitive to

A)infrared radiation.
B)light in the visible range.
C)phosphorescent light.

Question 58

Which of the following disorders of vision can be treated with LASIK surgery?

A)astigmatism
B)cataracts
C)glaucoma

Question 59

Describe the path of a single photon,from the time it is reflected to the eye,to the moment of transduction.What structures does it pass through,and how is its path altered at each step?

Question 60

Your text describes the receptive field as it pertains to vision,but it also applies to other senses.Explain how you would map the receptive field for a neuron connected to touch receptors in an animal's back.(Assume you have already inserted an electrode that is registering the neuron's activity. )