Where is the optic nerve head located and what is histologically notable there?

• A. At the macula; high cone density.
• B. At the optic disc; absence of photoreceptors and convergence of ganglion cell axons; lamina cribrosa present.
• C. At the fovea; thick photoreceptor layer.
• D. At the optic disc; prominent photoreceptor layer and no lamina cribrosa.

Answer: (C)