Canon EOS R10 User Manual page 451

3.
Aim the camera at the subject.
A tracking frame is displayed around their eye.
To choose an eye to focus on when [
area AF], either tap the screen or use <
tracking frame changes again to [
You can also tap the screen to choose an eye, when [
set to [Whole area AF] or during tracking in progress.
If your selected eye is not detected, an eye to focus on is selected
automatically.
4.
Take the picture.
Caution
Subject eyes may not be detected correctly, depending on the subject and shooting
conditions.
No tracking frame is displayed when [
[ : Subject to detect] is set to an option other than [None].
Eyes are not detected when [
: Subject tracking] is set to [Off], even if
: Subject to detect] is set to [None].
451
: AF area] is set to [Whole
>. As you use <
].
>, the
: AF area] is