The javascript blur() method is called on captcha buttons after being clicked to reload the captcha image or play the sound.
It's sadly a bit annoying on an accessibility point of view: the focus shouldn't be lost when using those buttons.
Just click on one on those two buttons and you will notice that focus is lost.
I haven't found any valid reason for that behavior, feel free to chime in if you know some reason it could behave like that.
A solution has been implemented that simply disables the blur() method on those buttons.
Validate MR.
Focus won't be lost anymore when clicking on the captcha buttons.
We can make this configurable if some people want to keep the original behavior:
Fixed
2.0
Code
It affects the ability of people with disabilities or special needs (such as blindness or color-blindness) to use Drupal.