<unk> s should be diagnosed by an eye care professional who can perform a thorough exam of the back of the eye using an ophthalmoscope. More recently, the development of a special technology called optical coherence tomography (OCT) has allowed better visualization of the retinal layers. It has been used to demonstrate a marked reduction in the thickness of the retinal nerve fiber layer in the quadrant corresponding to the<unk> . This is not yet in standard use for diagnosis of an<unk> , but may be helpful in supporting a diagnosis.
Optic pit
Optic cup 
Optic recess
Optic stalk
Optic vesicle
Scleral lens
Lacrimal groove
Corneal button