A child is found not to be able to see at night. What is the child suffering from.

Night blindness

From Google:

Night blindness is a type of vision impairment also known as nyctalopia. People with night blindness experience poor vision at night or in dimly lit environments. Although the term “night blindness” implies that you can't see at night, this isn't the case.

The child may be suffering from a condition called nyctalopia, commonly known as night blindness. Night blindness is a visual impairment where a person finds it difficult or impossible to see in low-light conditions or at night. This condition can be caused by various factors, including a deficiency in vitamin A, certain genetic disorders, and medical conditions such as retinitis pigmentosa or cataracts.

To determine if a child is suffering from night blindness, a medical professional would typically perform a comprehensive eye examination. This examination may include assessing the child's visual acuity, testing their ability to see in dimly lit environments, and checking for any underlying eye abnormalities or health issues. They may also ask the child and their parents about their medical history and any relevant symptoms.

It is important for the child and their parents to consult with an optometrist, ophthalmologist, or pediatrician to accurately diagnose and determine the appropriate treatment for night blindness. Depending on the underlying cause, treatment options can vary, such as prescribing vitamin A supplements, addressing any underlying health conditions, or recommending assistive visual aids to improve night vision.