The eye condition: non-arteritic anterior ischemic optic neuropathy (NAION)

Non-arteritic → Not involving arteries [0]

Anterior → Front part

Ischemic → Low blood flow

Optic → Related to the eye

Neuropathy → Nerve damage [1]

"Non-arteritic anterior ischemic optic neuropathy (NAION) refers to loss of blood flow to the optic nerve (which is the cable that connects the eye to the brain). This condition typically causes sudden vision loss in one eye, without any pain." - https://www.brighamandwomens.org/neurology/neuro-ophthalmolo...

[0] This differentiates it from a similar condition that does involve arteries

[1] More literally, nerve sickness

Thanks, chubbyemu ;)