<prompt> Thinnest portion of sclera -Anterior to rectus muscle insertionPosterior to rectus muscle insertionPosterior poleLimbus  <response>: Ans. is b i.e., Posterior to rectus muscle insertion o Thinnest portion of sclera - Posterior to insertions of rectus muscle.o Thickest portion of sclera - Posterior pole.o The thickness of the sclera varies according to location : -At the limbus, the sclera is 0?8 mm thick.Anterior to the rectus muscle insertions, it is 0?6 mm thick.Posterior to the rectus muscle insertions, it is 0?3 mm thick Thinnest portion.At the equator, it is 0?5 to 0?8 mm thick.At the posterior pole, it is greatest than 1 mm thick. 