Crows feet are the fan shaped lines and wrinkles that radiate out from the outside corner of the eye.
Crows feet are worsened when smiling, laughing or squinting.

Orbicularis Oculi muscle. This is the big ring shaped muscle, highlighted in the image, that surrounds the eye. The Orbicularis Oculi muscle contracts like a purse string around the eye which then accentuates the crows feet.

The patient sits back on a bed with the backrest up.
The area is cleaned.
The exact placing of the injection points are different between people and depends on the muscle action observed when wrinkling the forehead.In some people the crows feet radiates upwards, in some equally upwards and downwards and in some people mostly downward.
The muscles are injected.
It takes about 1-2 minutes.
Light pressure is applied to the area to prevent bruising.

Orbicularis Oculi muscle injection (highlighted in the image above) for crows feet:

Some patients experience a slight headache that can be relieved with Paracetamol.
Slight bruising can occur, but can be concealed with make-up. It resolves in a few days.
The effect will kick in after 7-10 days and last between 2 and 7 months, depending on the dosage used and the patients physiology. Some patients dissolve Toxin faster than other patients.
First time patients will sometimes be requested to return after 2-3 weeks for a check-up and an adjustment if required.
Most patients have the injections repeated 3-4 times a year.