Crow’s Feet

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Crow’s feet are the fine lines that fan out from the outer corners of the eyes, named for their resemblance to a bird’s footprint. Known medically as lateral canthal lines, they form from the repeated contraction of the muscle around the eye during everyday expressions such as smiling and squinting. Because they are driven largely by movement, they respond particularly well to botulinum toxin—which is why they are one of the most commonly treated areas in medical aesthetics.

Editorial macro of the outer corner of a woman's eye with smooth, luminous skin — crow's feet (lateral canthal lines) — Revel Beauty Club

At a glance

  • Also called: Lateral canthal lines
  • Where: Fanning outward from the outer corners of the eyes
  • Cause: Repeated contraction of the orbicularis oculi (the muscle that closes the eye), plus sun exposure and collagen loss
  • Type: Dynamic wrinkles at first (appear with expression), becoming static (visible at rest) over time
  • First-line treatment: Botulinum toxin—Health Canada–authorized for this area
  • Support: Sun protection, retinoids and resurfacing address the skin-quality component

What are crow’s feet?

Crow’s feet, or lateral canthal lines, are the small radiating lines at the outer corner of each eye.[3] They are a normal, universal sign of an expressive face—the same smiling and laughing that creates them is exactly what makes a face warm and animated. For many people they are simply a cosmetic concern they’d like to soften, rather than anything medical.

What causes crow’s feet?

The primary cause is muscle movement. Each time you smile or squint, the ring-shaped orbicularis oculi muscle around the eye contracts and folds the overlying skin; repeated over years, those folds settle into visible lines.[3] Two other forces make them worse over time: intrinsic aging, with the gradual loss of collagen and elastin that keep skin springy, and extrinsic factors—chiefly sun exposure and smoking—that accelerate skin breakdown.[3]

Dynamic versus static crow’s feet

Early on, crow’s feet are dynamic wrinkles—they appear when you smile and disappear when your face relaxes. With time, and as the skin loses collagen, they can become static wrinkles that remain etched even at rest.[3] This distinction guides treatment: muscle-relaxing injections work best on the dynamic component, while the static, skin-quality component may also need resurfacing or skincare.

How crow’s feet are treated

The standard first-line treatment is botulinum toxin type A. By temporarily relaxing the orbicularis oculi, it softens the movement that creates the lines.[1][3] Botox is Health Canada–authorized specifically for lateral canthal lines, and related products such as Dysport and Xeomin are used similarly.[2][4] At Revel, this is offered through our neuromodulator treatments; you can also read about Botox in Bloor West Village. Treatment is quick, and a skilled injector places small, precise doses to soften the lines while keeping a natural, expressive look.

What to expect: onset and duration

Results are not instant. The effect typically begins within a few days and develops fully over about two weeks, then lasts roughly three to four months before movement gradually returns.[1][4] Because the effect is temporary, maintaining smoother crow’s feet means repeating treatment periodically rather than a one-time fix.

Beyond botulinum toxin: skin quality

When crow’s feet have become static, muscle relaxation alone may not fully erase them, and the skin itself needs attention. Daily broad-spectrum sun protection is the single most important preventive step, and topicals such as retinoids and vitamin C support the underlying collagen. Resurfacing treatments can further improve fine lines and texture around the eyes. Often the best result comes from combining a muscle-relaxing injection with skin-quality care rather than relying on one alone.

Related glossary terms

Clinical & editorial sources

  1. Padda IS, Tadi P. Botulinum Toxin. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated 2023 Nov 6. NBK557387
  2. AbbVie Corporation. BOTOX COSMETIC (onabotulinumtoxinA) Product Monograph. Health Canada–authorized labelling. abbvie.ca
  3. Periorbital Botox: How to Treat Crow’s Feet. Harley Academy. harleyacademy.com
  4. DermNet. Botulinum toxin. DermNet (New Zealand). dermnetnz.org

This glossary entry provides general educational information and does not replace an individual clinical assessment or medical advice.

Clinically reviewed by: Leah Zawawi, RPN | Medical Aesthetics & Injectables.

Last reviewed: August 2026.

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