Try Stepping Back From the Screen

One of the easiest techniques is to physically move farther away from the image.

If you’re viewing it on a phone, hold the phone farther away.

If you’re looking at it on a computer, lean back slightly.

Reducing the apparent size of the image can make the larger shapes easier to recognize.

At close range, your brain may focus on individual lines.

From a distance, those details merge into larger forms.

That can make the outline of the hidden face easier to perceive.

Relax Your Eyes

Another useful technique is to stop forcing your eyes to focus sharply on every detail.

Instead, allow your gaze to become slightly relaxed.

Don’t stare at one particular rock.

Look at the image as a whole.

You can even briefly look away and then return to the picture.

This changes how your visual system processes the arrangement.

Sometimes the hidden image appears suddenly after your brain stops trying to analyze every component separately.