1) Blindness 2) Cecity 3) Defective vision 4) Sightlessness 
[n] - sightlessness (especially because of a structural defect in or the absence of an eye)
anopia Absence of sight; especially, when due to a structured defect in or absence of an eye (or eyes).
noun sightlessness (especially because of a structural defect in or the absence of an eye)
absence of sight, esp. when due to a structural defect in or absence of an eye.