Cured data – Using ClipPlanes with AnatomyData

Suppose I make a simple eyeball:

AnatomyPlot3D[Entity["AnatomicalStructure", "RightEyeball"]]

Anatomy diagram of the eyeball

But I want to cut it in half using ClipPlanes, for example, to eliminate the left half of the eyeball.

With what method of principles do I know how to specify the plane? I tried the obvious

ClipPlanes -> {1,0,0,0}


{{0,0,0}, {0,1,0}, {0,0,1}}