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The interactive dog atlas · Exterior and regions · Head

Eyelids palpebrae

The eyelids are the skin that closes the eye. The dog also has a third eyelid, in the corner toward the nose, which slides across the eye when the eye is drawn back.

Open in the interactive atlas Guide: Exterior Worksheet

Educational material, not a diagnostic tool. Written by the Mantrailing România team from veterinary sources we read. Updated 14.11.2026.

Dog in left lateral view — exterior, muscles, skeleton and organs Vector study after the Ellenberger, Baum and Dittrich plates: a standing dog, head to the left, deep chest and digitigrade limbs. The four layers use the same contour: exterior with body regions, superficial muscles, skeleton and organs.
  1. Eyelids
  2. Eye
Eyelids on the atlas drawing, "Exterior and regions" layer, with the neighbouring structures. Left lateral view, after the Ellenberger, Baum and Dittrich plates.

Where it is

Around the opening of the eye; the third eyelid in the corner toward the nose.

System
Body regions
Region
Head

What it is and what it does

The eyelids are mobile folds that protect the eye; their middle layer contains the fibers of the orbicularis oculi. In carnivores, the lower eyelid has no cilia. In the corner toward the nose sits the third eyelid, the nictitating membrane, supported by a T-shaped cartilage: its movement is passive, it is pushed across the cornea when the retractor muscle pulls the eyeball back; humans have neither a third eyelid nor this muscle.

Worth remembering

A third eyelid that stays visible for a long time is a reason to visit the vet, not to diagnose at home.

Names

Guides it appears in

From the same region: Head

All structures, in the atlas · Flashcards: exterior and regions