WorksheetsEye anatomy and the visual pathway 1
Total questions: 20
Worksheet time: 19mins
Which layer of the eyeball would be the first to be affected by deficient tear production?
Sclera
Choroid
Retina
A condition, called night blindness, dangerously impairs our ability to drive safely at night. Its most common cause is prolonged vitamin A deficiency, which eventually causes the neural retina to deteriorate. Vitamin A supplements will restore function if taken before degenerative changes in the neural retina occur. Which component of the eye is defected in this condition?
(a)
One of the most common forms of colour blindness are the two varieties of red-green colour blindness. In people who have red or green colour blindness, red and green are seen as the same colour. Many colour-blind people are unaware of their condition because they have learned to rely on other cues—such as differences in intensities of the same colour—to distinguish green from red, for example, on traffic signals. Which component of the eye is possibly defected in this condition?
(a)
Glaucoma is a condition in which the pressure within the eye may increase to dangerous levels and compress the delicate retina and optic nerve. It can lead to blindness unless detected early. Glaucoma is a common cause of blindness in the elderly. Glaucoma is caused by blockage of the drainage of the ……………………… (Fill in the blank)
(a)
Near-sightedness, or myopia (“short vision”), occurs when the parallel light rays from distant objects fail to reach the retina and instead are focused in front of it; see part (b) in the figure. Another way to think of this is the focal point of a myopic eye falls short of the retina. Therefore, distant objects appear blurry to myopic people. Nearby objects are in focus, however, because the lens “accommodates” (bulges) to focus the image properly on the retina. Correction requires concave corrective lenses that diverge the light rays before they enter the eye, so that they converge farther back on the retinal surface. In other words, near-sighted people see near objects clearly and need corrective lenses to focus on distant objects.
Which of the following is NOT the cause of myopia?
The eyeball is too long
The lens is too curved
The cornea is too curved
The ciliary muscle is too relaxed
Far-sightedness, or hyperopia (“far vision”), occurs when the parallel light rays from distant objects are focused behind the retina—at least in the resting eye; see part (c) in the figure. People with hyperopia see distant objects clearly because their ciliary muscles contract continuously to increase the light-bending power of the lens, which moves the focal point forward onto the retina. However, the diverging rays from nearby objects are focused so far behind the retina that even at full “bulge,” the lens cannot focus the image on the retina. Therefore, nearby objects appear blurry, and hyperopic individuals are subject to eyestrain as their endlessly contracting ciliary muscles tire from overwork. Correction of hyperopia requires convex corrective lenses that converge the light rays before they enter the eye. Thus, farsighted people can see faraway objects clearly and require corrective lenses to focus on nearby objects.
Which of the following is NOT the cause of hyperopia?
The eyeball is too short
The lens is too flat
The cornea is too flat
The proportion of rods/cones is abnormal
Why is using dioptres (1/f ) convenient?
As an object moves closer, do the ciliary muscles contract, or relax to keep the object in focus?
Given the three parameters (do, di and f), how does the human eye keep the world in focus?
Changing f
Keep a suitable ratio of do and di
Keep f as constant
Which eye structure determines a person’s eye color?
(a)
Which eye structure is comparable to the film of a camera because it senses light focused on it?
(a)
“Pink eye” is an inflammation of which eye tissue?
Lens
Conjunctiva
Sclera
Cornea
What is the primary (most powerful) focusing structure of the eye?
(a)
Eye floaters are spots in your vision. They may look to you like black or gray specks, strings, or cobwebs appeared when you look at a bright background such as white page or blue sky. These spots drift about when you move your eyes and disappear when you try to look at them directly. Most eye floaters are caused by age-related degeneration, which liquifies the the jelly-like substance of the (a) . Microscopic fibers within that part of the eye tend to clump and can cast tiny shadows on your retina. These shadows are called floaters.
Cataract is an eye disease that is caused when the crystalline structure of the ___________ become cloudy. Most cataracts related to aging. Cataract can be treated by the surgery which removes the clouded _________ and replaces it will an artificial one.
(a)
Which of the following correctly describes the pathway of light passing through the eye to the retina?
cornea, anterior chamber, pupil, posterior chamber, lens, posterior cavity, retina
cornea, anterior cavity, pupil, posterior cavity, lens, posterior chamber, retina
cornea, anterior chamber, iris, pupil, posterior chamber, lens, posterior cavity, retina
Which of the following statements is true?
Rods are more numerous than cones.
The fovea centralis area consists of only rods
Due to the location of rods in the retina, you can see objects at night better if you look straight at the object
The ciliary muscle is responsible for which function in the eye?
Varying the size of the pupil
Opening and closing the eyelid
Moving the eyeball left and right
The shaping of the lens
Where does light refract for a 2nd time, and focuses light on the retina?
Lens
Cornea
Pupil
Optic nerve
This area does not give the eye shape
sclera
Vitreous humour
aquaeous humour
cornea
pupil
