Crow’s feet can be classified into five levels according to their degree.
None: no visible wrinkles, only continuous lines of skin.
Mild: only visible when smiling, no visible lines when the face is not making expressions.
Moderate: Crow’s feet are static lines, with small lines at the corners of the eyes even when no expression is made.
Severe: the crow’s feet are so severe that they are deep and unconcealable even without expression.
Extreme: not only deep crow’s feet, but also lines with multiple divisions at the end of the lines and visible wrinkles.