Like the blood-brain barrier, this is only selectively permeable, keeping any toxins in the blood from reaching the delicate photoreceptors.
(of a membrane) selectively permeable.
The negative value of solute potential of a solution means if a solution is separated from pure water by a selectively permeable membrane.
Concentration by use of selectively permeable membranes is a rapidly developing technology that has found many applications in food processing.
