Difficulty adjusting to the dark can have various causes, ranging in severity from 'troubling' to '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:
|Zinc Need||5%||Ruled out|
|Vitamin A Need||5%||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.
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.