The vitreous membrane (or hyaloid membrane or vitreous cortex) is a layer of collagen separating the vitreous humour from the rest of the eye.

The posterior hyaloid membrane separates the rear of the vitreous from the retina.

It is a false anatomical membrane.

[1] The anterior hyaloid membrane separates the front of the vitreous from the lens.

[2] Bernal et al. describe it "as a delicate structure in the form of a thin layer that runs from the pars plana to the posterior lens, where it shares its attachment with the posterior zonule via Weigert's ligament, also known as Egger's line".