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
flagAustria
61%
7%
23%
7%
13
flagthe United States
46%
18%
21%
12%
282
flagCanada
46%
20%
26%
6%
15
flagthe United Kingdom
45%
18%
21%
14%
92
flagRussia
44%
28%
21%
5%
38
flagthe Philippines
43%
18%
25%
12%
16
flagPoland
40%
20%
22%
15%
12027
flagIndia
40%
27%
18%
12%
110
flagGermany
40%
27%
16%
14%
54
flagUnknown
38%
19%
28%
14%
21
flagUkraine
37%
22%
24%
14%
61
flagGreece
27%
18%
18%
36%
11
flagAustralia
20%
20%
25%
35%
20