Everything you should know about night blindness 

Night blindness, also known as nyctalopia, is when you have trouble seeing in dim or dark environments. It can happen if your eyes have trouble quickly adjusting to changes in brightness or have issues with detecting light.

Symptoms

Night blindness has more specific symptoms than just blurry or cloudy vision in low lighting, including:

• Difficulty seeing objects in dim lighting or at night.
• Light sensitivity (photophobia)
• Blurry vision in poor lighting.
• Glare, halos, or sensitivity to bright lights (especially headlights).
• Total vision loss when entering a dark room, lasting more than a few minutes 
• Not being able to see stars or very dim objects. 

Causes

Night blindness is usually a symptom of an underlying condition, not a disease on its own. It arises from problems that either prevent enough light from reaching the retina or interfere with how the retina detects light. 

1. Refractive errors

Nearsightedness (myopia) or uncorrected vision problems can blur vision, especially at night. 

2. Cataracts

Clouding of the eye’s lens prevents light from reaching the retina clearly, affecting night vision first. 

3. Retinal diseases

Retinitis pigmentosa and similar inherited retinal disorders attack the rod cells responsible for dim-light vision. 

4. Glaucoma

Increased pressure in the eye can damage the optic nerve and reduce vision, including night vision. Some glaucoma medications may also contribute.

5. Vitamin A deficiency

Vitamin A is essential for producing rhodopsin, a pigment in rod cells that helps the eyes adapt to darkness. Its deficiency is a major cause worldwide. 

6. Diabetes and diabetic retinopathy

High blood glucose can damage blood vessels in the retina, leading to night vision difficulties as part of diabetic retinopathy.

7. Genetic or congenital forms

Some people are born with conditions that impair their rods or retinas (e.g., congenital stationary night blindness). 

8. Post-surgical or other conditions

Refractive surgeries (like LASIK) or diseases affecting the retina can also worsen night vision. 

Diagnosis and Treatment 

Night blindness is diagnosed by an eye-care professional through:

• Comprehensive eye examination (visual acuity, retinal evaluation). 

• Contrast sensitivity testing or specialized retinal tests. 

• Sometimes, blood tests (e.g., vitamin A or glucose levels) to identify underlying causes. 

Because night blindness is a symptom, treatment targets the underlying cause:

Corrective lenses: Updated glasses or contact lenses can improve night vision if refractive error is the cause. 

Cataract surgery: Removing a cloudy lens and replacing it with a clear artificial lens often improves night vision significantly. 

Managing eye diseases: Glaucoma: Eye drops, lasers, or surgery to control pressure. 

Diabetic Retinopathy: Controlling blood sugar and eye-specific treatments.

Vitamin A therapy: In cases of deficiency, vitamin A     supplements or dietary changes can reverse night blindness.

Prevention & lifestyle tips

Some of the measures you can take if you’re not yet experiencing night blindness include: 

• Eating vitamin A-rich foods (leafy greens, carrots, sweet potatoes). 

• Regular eye examinations to detect defects early. 

• Managing chronic conditions like diabetes. 

• Protecting eyes from UV light with sunglasses to reduce cataract risk.