Congenital pit in optic nerve causes

Optic disc pit - vision is normal in the absence of complications. The disc is often larger than normal and contains a greyish round or oval pit of variable size , usually temporal but occasionally central. Visual field defects are common and may mimic glaucoma. Serous macular detachment develops in about half of eyes with non-central disc pits. Ref: kanski's 8th edition, page no.798