Cotton wool, or absorbent cotton as it is now technically named by the British Pharmacopoeia, is a downy material made from the hairs on cotton plant seeds (Gossypium herbaceum). It is used in medicine in wound-dressing packs, skin-cleaning procedures, etc.
soft fluffy spots in the retina resulting from accumulations of *axoplasm in the nerve-fibre layer of the retina. These may indicate diseases causing hypoxia (oxygen deficiency) in the nerve-fibre layer (e.g. diabetes, hypertension, connective-tissue disease, or AIDS).... cotton-wool spots