Night blindness

Can be caused by many disease processes, both inherited and acquired. Differentials that may cause blurred vision made worse by low light levels (e.g., cataracts, myopia, glaucoma) need to be distinguished from true night blindness.

Most commonly reported by patients with inherited retinal or choroidal dystrophies; rarely associated with an underlying malignancy.

Slit-biomicroscopy and electroretinography are often essential in narrowing the differential diagnosis.

Vitamin A deficiency can cause night blindness and is often overlooked in patients with malabsorption and malnutrition.

Vitamin A may be used to treat both genetic and acquired night blindness.

Night blindness is the inability of the eye to adapt to reduced illumination, leading to a complaint of not being able to see at night or in dim light. No standard classification system exists for night blindness. The conditions within this topic are divided into those with an underlying genetic cause and acquired conditions (i.e., occurring secondarily to an underlying systemic disease). The inherited conditions causing night blindness affect the structures within the retina or choroid, and are referred to as retinal or choroidal dystrophies. Cochrane Eyes and Vision Group: glossary Opens in new window It is important to establish the difference between true night blindness, which is when the patient experiences loss of vision in a dark environment, and blurred vision made worse by low light levels, which may occur if the patient has cataracts, myopia, or glaucoma.