Many times, an<unk>  is asymptomatic and is just an incidental finding on examination of the eye by a physician. However, some patients may present with the symptoms of a posterior vitreous detachment or serous retinal detachment. This is because<unk> s are associated with these disorders and are even speculated to be the actual cause of these disorders when they arise in patients with<unk> s (see "Associated Retinal Changes" below for a more in-depth discussion on this theory). The most common visual field defects include an enlarged blind spot and a scotoma. Visual acuity is typically not affected by the<unk>  but may get worse if serous detachment of the macula occurs. Metamorphopsia (distorted vision) may then result.<unk> s were first described in 1882 as dark gray depressions in the optic disc. They may, however, appear white or yellowish instead. They can also range greatly in size (e.g. some can be minuscule while others may be large enough as to occupy most of optic disc surface).<unk> s are associated with other abnormalities of the optic nerve including large optic nerve size, large inferior colobomas of the optic disc, and colobomas of the retina. The optic disc originates from the optic cup when the optic vesicle invaginates and forms an embryonic fissure (or groove).<unk> s may develop due to failure of the superior end of the embryonic fissure to close completely.
Optic pit
Optic cup 
Optic recess
Optic stalk
Optic vesicle
Scleral lens
Lacrimal groove
Corneal button