The role of the ocular lens in the regulation of intraocular pressure.

The relationship between lenticular colloid osmotic (oncotic) pressure and intraocular pressure is discussed, with particular reference to a postulated buffering reservoir action of the lens in protecting against acute changes in intraocular pressure. A hypothesis is developed regarding acute lenticular volume changes in those species manifesting change in lens shape during accommodation. The unusually high colloid osmotic pressure of fish lenses is discussed and related to their unique means of accommodation and their susceptibility to cataract formation.