Night Blindness
Your eyes are more sensitive to darkness than most, reducing your visual range by (IE) × 10 feet in twilight or darker environments. This also affects Darkvision if applicable.
Real-world Examples
Cataracts, Retinitis Pigmentosa, Usher Syndrome
Assistive Options
The only assistance for this is a brighter light source.
Magical Assistance
Goggles of Night or other magic items that grant Darkvision can assist with Night Blindness while worn, but they cause strain to those with Night Blindness and can only be worn for an hour, requiring a short rest afterward to avoid exhaustion.