<prompt> The sclera is thinnest atLimbusEquatorOptic nervePosterior to attachment of superior rectus  <response>: The sclera is thickest near the optic nerve, where it is approximately 1 mm in thickness The sclera is thinnest 0.3 mm posterior to the rectus muscle inseions and thickest 1.0 mm at the posterior pole near the optic nerve head. Thinnest at the inseion of extraocular muscles 0.3 mm Reference: khurana 6th edition pg 788 