aberrant formation or incomplete differentiation of the paired almond-shaped glands, one for each eye, that secrete the aqueous layer of the tear film; each lacrimal gland develops through branching morphogenesis regulated by FGF signaling; at E12.5, the conjunctival epithelium at the temporal side of the mouse eyes invades the Fgf10-expressing mesenchyme to form the initial lacrimal gland bud; the bud elongates posteriorly until E15.5 when secondary branching begins to establish the complex tubuloalveolar structure; this eventually gives rise to the mature lacrimal gland composed of numerous ducts, acini and connective tissue