Getty Images

How Much Do You Know About Eye Anatomy?

Take our quiz to test your knowledge of this incredible organ

Sarah Elizabeth Adler,

Updated November 29, 2022

AARP

En español

Published September 28, 2021

/ Updated November 29, 2022

10 Questions

04889f39-31a1-4c9f-b883-734dbc7e19b4

How Much Do You Know About Eye Anatomy?

[ {
 "question" : "The “white of the eye” is also called the:\n",
 "answers" : [ {
 "answer" : "Cornea",
 "correctAnswer" : false
 }, {
 "answer" : "Lens",
 "correctAnswer" : false
 }, {
 "answer" : "Sclera",
 "correctAnswer" : true
 }, {
 "answer" : "Vitreous",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "The sclera, or white of the eye, is composed of collagen fibers and serves as the eye’s outer protective layer. Changes to this part of the eye can also signal health problems. For example, a yellowing of the sclera can indicate jaundice, while inflammation is sometimes a sign of rheumatoid arthritis.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "The cornea is a _________________ tissue located at the front of the eye.\n",
 "answers" : [ {
 "answer" : "Thin",
 "correctAnswer" : false
 }, {
 "answer" : "Clear",
 "correctAnswer" : false
 }, {
 "answer" : "Curved",
 "correctAnswer" : false
 }, {
 "answer" : "All of the above",
 "correctAnswer" : true
 } ],
 "multiSelect" : false,
 "explanation" : "The transparent, dome-shaped cornea focuses light as it enters the eye. Unlike other body parts, the cornea doesn't have its own blood supply (it receives oxygen from the air). It does have nerve endings, however, which is why scratching your eye can hurt!\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "The clear fluid found behind the cornea is known as:\n",
 "answers" : [ {
 "answer" : "Cerebrospinal fluid",
 "correctAnswer" : false
 }, {
 "answer" : "Aqueous humor",
 "correctAnswer" : true
 }, {
 "answer" : "Vitreous",
 "correctAnswer" : false
 }, {
 "answer" : "Interstitial fluid",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "Aqueous humor fills small chambers behind the cornea, nourishing the eye and helping retain pressure to keep the eye inflated. The eye constantly produces and drains an equal amount of this liquid. Imbalances in this flow can lead to high intraocular pressure and damage vision, as happens with glaucoma.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "This part of the eye is dilated during an eye exam:\n",
 "answers" : [ {
 "answer" : "Iris",
 "correctAnswer" : false
 }, {
 "answer" : "Pupil",
 "correctAnswer" : true
 }, {
 "answer" : "Retina",
 "correctAnswer" : false
 }, {
 "answer" : "Lens",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "The pupil allows light to enter the eye, getting bigger in low-light conditions and smaller in bright light. During an eye exam, dilating eye drops are used to keep the pupils enlarged so that your provider can look inside your eyes. (Fun fact: Pupils are not actually black — they just appear that way because light entering the eyes is not reflected back out.)\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "All of the following are true of the iris, or colored part of the eye, except that:\n",
 "answers" : [ {
 "answer" : "It influences cataract formation.",
 "correctAnswer" : true
 }, {
 "answer" : "It controls how much light is let into the pupil.",
 "correctAnswer" : false
 }, {
 "answer" : "Its color is determined by genetics.",
 "correctAnswer" : false
 }, {
 "answer" : "It contains the same pigment found in skin and hair.",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "The iris, or colored part of the eye, uses muscles to expand the pupil (letting in more light) in low-light conditions or to make it smaller in bright light. Like your eye color? You can thank your genes, which control the pigment called melanin (the same one found in skin and hair) that determines whether your eyes are brown, hazel, green or blue.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "After light passes through the pupil, it hits the _________________:\n",
 "answers" : [ {
 "answer" : "Ciliary muscles",
 "correctAnswer" : false
 }, {
 "answer" : "Vitreous",
 "correctAnswer" : false
 }, {
 "answer" : "Lens",
 "correctAnswer" : true
 }, {
 "answer" : "All of the above",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "After entering the eye through the cornea, light passes through the pupil and reaches the lens, a transparent structure that helps focus light on the retina, located in the back of the eye. Small muscles called ciliary muscles are attached to the lens and help it change shape depending on whether we’re looking at something up-close or at a distance. Clouding of the lens results in cataracts.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "The gel-like substance that fills the space behind the lens is called vitreous.\n",
 "answers" : [ {
 "answer" : "True",
 "correctAnswer" : true
 }, {
 "answer" : "False",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "Vitreous is the clear, gel-like substance that fills the back portion of the eye, behind the lens. Also called vitreous humor, vitreous helps the eye keep its shape and allows light to pass through the eye to the retina. (The word “vitreous” is derived from the Latin “vitrum,” meaning glass.)\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "Macular degeneration affects this light-sensitive part of the eye:\n",
 "answers" : [ {
 "answer" : "Retina",
 "correctAnswer" : true
 }, {
 "answer" : "Iris",
 "correctAnswer" : false
 }, {
 "answer" : "Pupil",
 "correctAnswer" : false
 }, {
 "answer" : "Lens",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "The retina is a thin tissue layer that lines the back wall of the eye. It contains cells called photoreceptors that convert light into electrical signals that are sent to the brain. Macular degeneration occurs when the macula, the center portion of the retina responsible for sharp, straight-ahead vision, is damaged.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "The two types of photoreceptors are rods and cones. Rods are responsible for _____ ___; cones are responsible for _________.\n",
 "answers" : [ {
 "answer" : "Up-close vision; distance vision",
 "correctAnswer" : false
 }, {
 "answer" : "Low-light vision; color vision",
 "correctAnswer" : true
 }, {
 "answer" : "Distance vision; up-close vision",
 "correctAnswer" : false
 }, {
 "answer" : "Color vision; low-light vision",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "Rods are located mostly at the outer areas of the retina and are highly light-sensitive, allowing us to see in low-light conditions, such as at night. They also help with peripheral vision. Cones are found in the center of the retina and enable us to see fine detail as well as color.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "Which nerve transmits signals from the retina to the brain?\n",
 "answers" : [ {
 "answer" : "Visual nerve",
 "correctAnswer" : false
 }, {
 "answer" : "Vagus nerve",
 "correctAnswer" : false
 }, {
 "answer" : "Trigeminal nerve",
 "correctAnswer" : false
 }, {
 "answer" : "Optic nerve",
 "correctAnswer" : true
 } ],
 "multiSelect" : false,
 "explanation" : "The optic nerve is located at the back of the eye and sends input from the retina to the brain’s visual cortex, which turns these electrical signals into the images we see. In other words, we “see” with our brains — and according to researchers at MIT, almost half of our brain capacity is devoted to processing visual information.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
} ]

Quiz Progress

0 Correct

0 Incorrect

get help and give help through AARP Community Connections

Caption for quiz image

Credit for quiz image

NEED A HINT?

CLOSE HINT

CORRECT

INCORRECT

Answer:

How Much Do You Know About Eye Anatomy?

0 Correct

0 Incorrect

Score:

Oops...something went wrong. Please log out and log back in to continue.

Sarah Elizabeth Adler is a writer based in Washington, D.C. She has written about science, art and culture for outlets including aarp.org, where she was previously a staff writer, The Atlantic and California magazine.