C O H Z V

 1.0

S Z N D C

 0.9

V K C N R

 0.8

K C R H N

 0.7

Z K D V C

 0.6

H V O R K

 0.5

R H S O N

 0.4

K S V R H

 0.3

H N K C D

 0.2

N D V K O

 0.1

D H O S Z

 0.0

V R N D O

-0.1

C Z H K S

-0.2

O R Z S K

-0.3

Visual acuity test

My little joke aside, the definitely not a medical test works as follows. First, you should enter the distance (in cm) between your eyes and the screen inside the text field at the top of the page. If you're at an arm's length from the screen, that'd be about 70 cm. Then, pick up the line with the smallest font size that you can still see clearly. If you see the line with '0.0' to the right - congratulations, it is likely that your visual acuity is normal. If not - don't panic and see the accompanying blog post.