“Happy people” have crow’s feet, hence these are also known as laughter lines or smile lines.
Crow’s feet are the fine crinkle lines or wrinkles clustered at the outer corners of the eyes which appear with age from as early as the mid 30s.
As well as age and having a genetic tendency to develop crow’s feet, external factors such as sun exposure especially in fair-skinned people, pollutants, and smoking all contribute to causing thinning of the overlying skin with less production of elastin and collagen.
The fine underlying orbicularis muscle contractions form visible dynamic crow’s feet wrinkles.
Initially, the crow’s feet are only visible on active smiling (dynamic), but with time (age) they remain permanently as fine lines radiating outwards from the outer corners of the eyes even when not smiling (static lines).
The depth and number of crow’s feet increase with age and start to radiate out beyond the orbital rim onto the zygomatic arch and upper cheeks, often forming broad arcs of wrinkles.
Botox (Botulinum toxin A) is used to treat crows feet.