Visual System: The Eye

Directions:
Select the BEST response alternative for each of the questions below.

	1.	What is one visual advantage that some birds and bees have over humans?
		A)	The ability to see ultraviolet light.
		B)	Better depth perception.
		C)	The ability to see gamma radiation.
		D)	All of the above.
	2.	The outside surface of the eye, a protective membrane covering the eye that gives the eye its characteristic white appearance, is known as the:
		A)	iris.
		B)	pupil.
		C)	zonule.
		D)	sclera.
	3.	The process of adjusting the lens of the eye so that both near and far objects can be seen clearly is:
		A)	accommodation.
		B)	the pupillary reflex.
		C)	macular closure.
		D)	dark adaptation.
	4.	Zonule fibers and the ciliary muscles work to:
		A)	stretch the retina to be thin enough to allow light to pass through it.
		B)	ensure that the cornea is clear of materials, such as hair and other debris.
		C)	change the curvature of the lens, allowing accommodation.
		D)	adjust the amount of fluid in the posterior chamber.
	5.	Which term names the fovea and its surrounding area?
		A)	Foveal junction.
		B)	Anterior chamber.
		C)	Macula.
		D)	Optic disc.
	6.	What is retinal?
		A)	A derivative of vitamin A.
		B)	A protein found in cones.
		C)	A wall dividing the lens and the retina.
		D)	A muscle attaching the retina to the lens.
	7.	Javier is walking through his yard in deep twilight. Which of the following statements most accurately describes the visual system or systems he is using?
		A)	He is relying on the photopic system, which is associated with the cones, because cones are sensitive to color.
		B)	He is relying on the scotopic system, which is associated with the rods, because rods are more sensitive to light than cones are.
		C)	He is relying on the Purkinje shift to adjust to the decreasing levels of light available to his eyes.
		D)	He is relying on both the photopic and scotopic systems because it is a time of intermediate light intensity.
	8.	The Purkinje shift is the observation that:
		A)	photopic vision is less sensitive to color than scotopic vision.
		B)	long wavelength light excites the L-cone more than short-wavelength light does.
		C)	short wavelengths tend to be relatively brighter than long wavelengths in scotopic vision compared to photopic vision.
		D)	people with color deficiencies shift to greater dependence on scotopic at higher light levels than people with normal color vision.
	9.	Spatial summation is the:
		A)	ability to pool light across different regions of space.
		B)	ability to resolve light to particular locations in the visual world.
		C)	process of adapting sensitivity to match visual conditions.
		D)	process of adapting focus based on physical distance.
	10.	What is a receptive field?
		A)	The range of wavelengths to which a particular sensory neuron responds.
		B)	The area in the visual world to which a particular sensory neuron responds.
		C)	The range of intensities to which a particular sensory neuron responds.
		D)	The range of speeds at which a particular sensory neuron reacts.
	11.	What is the goal of lateral inhibition?
		A)	Mediating on-center surround cells.
		B)	Facilitating edge detection.
		C)	Overriding illusory processes.
		D)	Integrating figure and ground.
	12.	Harry is a 90-year-old man. He shows impaired visual acuity and color vision in both eyes, though his peripheral vision is unimpaired. He has difficulties reading even with powerful reading glasses. Your diagnosis?
		A)	Retinitis pigmentosa.
		B)	Cataracts.
		C)	Macular degeneration.
		D)	Heterochromia.

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The correct answers are marked by a "C" in the box before each question. The incorrect questions are marked by an "X".