Which of the lines on the right, is the continuation of the black line on the left?

red one
blue one
none of them
both of them
This is known as Poggendorff illusion, first described in 1860. Many detailed studies of the illusion point to its principal cause: acute angles in the figure are seen by viewers as expanded.
globalquiz.org
0
Correct this question
3
Very interesting!
 globalquiz.org
reach: rather globalillusionsoptical illusionstechnology

Answers by country

red one
blue one
none of them
both of them
answers
flagthe Netherlands
63%
9%
9%
18%
11
flagSwitzerland
50%
14%
7%
28%
14
flagCanada
47%
15%
31%
5%
19
flagthe United States
45%
19%
21%
12%
323
flagIndia
45%
23%
15%
14%
152
flagBelarus
43%
8%
39%
4%
23
flagRepublic of Ireland
43%
12%
25%
18%
16
flagthe Philippines
43%
18%
25%
12%
16
flagPoland
41%
20%
22%
15%
13582
flagUkraine
41%
16%
25%
16%
139
flagthe United Kingdom
41%
22%
20%
16%
118
flagAustria
41%
18%
24%
15%
53
flagGermany
40%
26%
20%
10%
234
flagUnknown
40%
18%
27%
13%
22
flagRussia
39%
20%
25%
14%
107
flagFrance
33%
25%
16%
25%
12
flagGreece
31%
21%
15%
31%
19
flagKazakhstan
30%
23%
23%
23%
13
flagAustralia
20%
20%
29%
29%
24