Difficulty adjusting to the dark can have various causes, ranging in severity from 'troubling' to 'very serious'. Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.
Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms. In order to diagnose difficulty adjusting to the dark, we could:
|Vitamin A Need||4%||Ruled out|
|Retinitis Pigmentosa||4%||Ruled out|
Vision - poor dark adaptation. Do you have difficulty seeing things when going from the light into a darkened room?
Possible responses:→ No / don't know
→ Mildly - can see well after very brief adjustment
→ Moderately - I need time to adjust
→ Seriously - can see only a little after a while
→ Severely - can see nothing at all
Cataracts, characterized by cloudiness of the lens, can cause night blindness.
Reduced night vision can be linked to a variety of conditions caused by impaired liver function which in turn reduces vitamin A metabolism.
Retinitis pigmentosa results in visual rods being destroyed early in the course of disease, resulting in night blindness. Night blindness in children may be an early indicator of retinitis pigmentosa.
Night blindness is commonly caused by a deficiency in vitamin A. It is considered one of the first indicators of vitamin A deficiency.
Zinc is required in order to transport vitamin A from the liver to the retina and thus zinc supplementation, especially in those who are deficient, should help improve night vision.