Baggy eyelids have a single anatomical basis.
Putterman
Allen M
AM
D000273:Adipose Tissue; D019882:Blepharoplasty; D005141:Eyelid Diseases / Q000209:etiology* / Q000601:surgery; D006801:Humans; D009915:Orbit; D011391:Prolapse; D015595:Skin Aging / Q000502:physiology*