Getty Images

QUIZ: Amazing Facts About Your Eyes

Michelle Crouch,

AARP

En español

Published March 10, 2023

10 Questions

e780f7fd-1d7f-40b6-84b1-595b8d4bba26

QUIZ: Amazing Facts About Your Eyes

[ {
 "question" : "True or false: The fastest-moving muscle in the human body is in the eye.\n",
 "answers" : [ {
 "answer" : "True",
 "correctAnswer" : true
 }, {
 "answer" : "False",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "A muscle called the orbicularis oculi, which controls the closing action of the eyelid, is the fastest human muscle, according to Guinness World Records.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "Which of the following activities is likely to increase blinking?\n",
 "answers" : [ {
 "answer" : "Fighting with your spouse",
 "correctAnswer" : true
 }, {
 "answer" : "Reading something interesting",
 "correctAnswer" : false
 }, {
 "answer" : "Watching an action sequence in a movie",
 "correctAnswer" : false
 }, {
 "answer" : "Staring at a screen",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "Studies show that people generally blink less when they are reading, watching or listening to something interesting, and blink more when they feel anxious and frustrated.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "At what distance can the human eye detect a candle flame on a dark night?\n",
 "answers" : [ {
 "answer" : ".75 mile",
 "correctAnswer" : false
 }, {
 "answer" : "1.6 miles",
 "correctAnswer" : true
 }, {
 "answer" : "17.3 miles",
 "correctAnswer" : false
 }, {
 "answer" : "30 miles",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "Although some internet sites claim the naked eye can see a flame as far away as 30 miles, Texas A&amp;M scientists calculated in 2015 that a candle would disappear from view at about 1.6 miles.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "True or false: We have microscopic creatures living in our eyelashes.\n",
 "answers" : [ {
 "answer" : "True",
 "correctAnswer" : true
 }, {
 "answer" : "False",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "Almost all of us have tiny, harmless mites living in or close to the hair follicles near our eyes and eyelashes. Called Demodex, or eyelash mites, they feed on oils and dead skin cells.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "How far away is the farthest object we can see with our naked eye?\n",
 "answers" : [ {
 "answer" : "12 million miles",
 "correctAnswer" : false
 }, {
 "answer" : "17 million miles",
 "correctAnswer" : false
 }, {
 "answer" : "25 trillion miles",
 "correctAnswer" : false
 }, {
 "answer" : "13 million trillion miles",
 "correctAnswer" : true
 } ],
 "multiSelect" : false,
 "explanation" : "The Andromeda Galaxy, a huge spiral galaxy outside the Milky Way, is about 2.5 million light years away, or 13 million trillion miles.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "How many different colors can the human eye detect?\n",
 "answers" : [ {
 "answer" : "1 million",
 "correctAnswer" : false
 }, {
 "answer" : "5 million",
 "correctAnswer" : false
 }, {
 "answer" : "10 million",
 "correctAnswer" : true
 }, {
 "answer" : "25 million",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "Scientists estimate that humans can distinguish up to 10 million different shades of color.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "Which of these is true about the 8 to 10 percent of people in the world who have blue eyes?\n",
 "answers" : [ {
 "answer" : "They have a single, common ancestor",
 "correctAnswer" : true
 }, {
 "answer" : "They are at lower risk of alcoholism",
 "correctAnswer" : false
 }, {
 "answer" : "They were more common about 10,000 years ago",
 "correctAnswer" : false
 }, {
 "answer" : "They are often born with eyes of a different color",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "All people with blue eyes descended from a single common ancestor who lived 6,000 to 10,000 years ago and developed a genetic eye color mutation, according to a 2008 University of Copenhagen study.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "Your iris has approximately how many unique characteristics?\n",
 "answers" : [ {
 "answer" : "45",
 "correctAnswer" : false
 }, {
 "answer" : "82 ",
 "correctAnswer" : false
 }, {
 "answer" : "256",
 "correctAnswer" : true
 }, {
 "answer" : "304",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "The iris — the colored part of your eye that regulates pupil size — has over 256 unique characteristics, compared with about 40 for a fingerprint.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "What can men see better than women?\n",
 "answers" : [ {
 "answer" : "Colors",
 "correctAnswer" : false
 }, {
 "answer" : "Up-close objects ",
 "correctAnswer" : false
 }, {
 "answer" : "Movement",
 "correctAnswer" : true
 }, {
 "answer" : "Objects at night",
 "correctAnswer" : false
 } ],
 "multiSelect" : false,
 "explanation" : "While women see more colors, studies show that men are better at detecting rapidly moving objects.\n",
 "hint" : "",
 "hintLink" : "",
 "questionImgCaption" : "",
 "questionImgCredit" : ""
}, {
 "question" : "True or false: The eye is the most complex organ in the human body.\n",
 "answers" : [ {
 "answer" : "True",
 "correctAnswer" : false
 }, {
 "answer" : "False ",
 "correctAnswer" : true
 } ],
 "multiSelect" : false,
 "explanation" : "The eye is actually the second most complex organ, after the brain. It has more than 2 million working parts.\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:

QUIZ: Amazing Facts About Your Eyes

0 Correct

0 Incorrect

Score:

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

Michelle Crouch is a North Carolina-based writer who has covered health issues for Reader’s Digest, The Washington Post and other publications. She has written for the Bulletin for more than a decade.