Botox for crow's feet: lines around the eyes

The lines that fan out from the outer corner of the eyes are called crow's feet. They are usually the first expression lines to appear — often before thirty — and there is an anatomical reason for that.

The skin around the eyes is the thinnest on the face. The muscle underneath it, the orbicularis, contracts with every blink, every smile, every time the light is too bright. It is thin skin combined with the most frequent movement in the face.

Why crow's feet show up first

The three factors

• Frequency of movement. We blink thousands of times a day, and every blink folds the skin in that area.
• Skin thickness. Less collagen and less support mean the fold sets in faster.
• Sun exposure. It is one of the areas that takes the most direct sun, and photoaging degrades what collagen is left.

Worth noting what this implies: crow's feet on their own are not a sign of advanced aging. They appear early in people who smile a lot and in people with fair, thin skin, and they often coexist with a face that otherwise shows no signs yet.

What Botox for crow's feet does

Botulinum toxin registered with Anvisa, the Brazilian health regulator, relaxes the lateral portion of the orbicularis muscle, reducing the force of the contraction that folds the skin. The line softens and, over time, the skin has a chance to recover partially from the repeated folding.

What it does not do: erase a mark already set at rest, or improve the quality of skin with accumulated sun damage. That calls for a different route — collagen stimulation, technologies, and consistent topical care.

The limit in this area, and it is a narrow one

Here is the part that separates a good result from one you can spot across a room.

Why a smile needs the eyes

A genuine smile involves contraction of the orbicularis. That is why we recognise a real smile — the eyes take part in it. Fully blocking that muscle produces a smile in which only the mouth moves, and the effect is unsettling in a way people notice without being able to name.

The correct goal around the eyes is to soften the line while preserving the participation of the eyes in the smile. That means a conservative dose and points chosen with judgement — not a maximum dose.

It is one of the areas where treating less delivers a better result, not merely a safer one.

Risks specific to this area

• Diffusion into the zygomatic muscle, which can alter the smile or produce asymmetry. It depends on how far the points sit from the musculature of the mouth.
• Bruising, more frequent here because of superficial vascularisation and thin skin.
• Transient asymmetry, when one side responds before the other.
• More visible lines on the lower eyelid in some people, when the lower orbicularis is relaxed excessively.

All are temporary. The last one is what most surprises anyone who was not warned.

How long it lasts

Three to four months, one of the shortest durations in the face. The reason is the same one that makes the wrinkle appear early: the muscle is thin and in constant movement, which speeds up the recovery of function.

Anyone treating crow's feet and glabella in the same session will notice the eyes returning to movement first. That is physiology, not failure.

Prevention counts for more here than anywhere else

Since the main external aggressor is the sun, two simple measures change the course:

What to do

• Daily sunscreen in the area, including on cloudy days and indoors under screen light.
• Sunglasses with UV protection. Beyond the filter, they cut the habit of squinting against bright light — which is a meaningful part of the movement that marks the skin.

No toxin treatment makes up for the absence of those two things.

When we advise against it

• When the mark is static and deep. Toxin keeps it from getting worse and does little for what is already set. Promising to eliminate it in that situation is dishonest.
• A high dose to "settle it for good". That is the direct route to a smile that never reaches the eyes.
• Treating this area alone when the real complaint is skin quality. Sun-damaged skin, uneven texture and dehydration do not improve with muscle relaxation.
• A touch-up before day fifteen, as with any toxin treatment.
• When there is evident eyelid laxity. Relaxing muscle in an eyelid that already lacks support can accentuate the problem, and the indication may be surgical — outside the scope of a dental surgeon, with a referral.

Frequently asked questions

How many units of Botox for crow's feet?

It varies with the strength of the musculature and the intended result. There is no standard number, and in this area a conservative dose usually delivers a better result than a high one.

Does Botox in the crow's feet change the smile?

It should not change the mouth. It should reduce the formation of the lateral lines while preserving the participation of the eyes. An altered smile points to diffusion into neighbouring musculature or poorly chosen points.

Can crow's feet be treated without Botox?

Skin quality can be improved with collagen stimulation, technologies and topical care, which softens the appearance. But the dynamic line, which comes from movement, only responds to muscle modulation.

What age can I start?

There is no fixed age. The criterion is the presence of a marked dynamic line that tends to become static. Treating someone with no line at all prevents nothing.

Does filler fix crow's feet?

It is not the indication. The area has very thin skin and constant movement — filler there tends to produce visible irregularity. The problem is one of movement, not volume.