Night Glare: A Warning Sign of Uncorrected Astigmatism?

Night Glare May Be Caused by Uncorrected Astigmatism

Glare while driving at night—seeing halos around headlights or streetlamps—is a common complaint that’s often overlooked. However, this may signal uncorrected astigmatism, one of the top causes of impaired nighttime vision.

Nighttime light scatter simulating astigmatic vision

What Is Astigmatism and Why Does It Affect Night Vision?

Astigmatism is a refractive error caused by an irregular curvature of the cornea or lens. This causes light to focus unevenly, producing blurred, distorted, or stretched images. Unlike nearsightedness or farsightedness, astigmatism affects both near and far vision and becomes especially disruptive in low-light conditions like nighttime.

Why Is Glare More Common at Night?

• Dilated Pupils: Pupils expand in dim light, exposing more of the irregular optical surface and amplifying distortion.
• Light Scatter: Bright sources like headlights scatter due to uneven corneal curvature, forming halos or glare.
• Reduced Contrast Sensitivity: Astigmatism blurs images, and combined with lower nighttime contrast, makes it harder for the brain to process sharp visuals.

Signs Your Astigmatism Is Not Properly Corrected

Person with eye strain from uncorrected astigmatism

• Eye strain or headaches after prolonged reading or driving
• Seeing halos or glare around lights at night
• Difficulty judging distance while driving
• Struggling to focus in dim lighting

Table: Comparison Between Corrected and Uncorrected Astigmatism

Factors That Worsen Night Glare

• Worn-out or incorrect prescription glasses/lenses
• Irregular eye exams
• Thin or damaged corneas
• Chronic dry eyes increasing light scatter

Effective Astigmatism Correction Methods

1. Advanced Refraction Testing

Routine eye exams detect astigmatism accurately, including irregular types that basic tests may miss.

2. Wearing Corrective Lenses

Properly prescribed glasses or contacts correct astigmatism effectively. For high astigmatism or nighttime drivers, more advanced solutions may be required.

3. Refractive Surgery – Especially Phakic ICL

Eye structure illustration with Phakic ICL intraocular lens

• No corneal cutting: Phakic ICL is a lens placed behind the iris, in front of the natural lens, correcting astigmatism without affecting corneal structure.
• Effective for 1D–4D astigmatism
• Significantly improves night vision: Its stable optical design reduces halos and glare.
• Removable if needed: Offers future flexibility for patients.

Choosing the Right Treatment Option

From Clear Daylight to Safer Night Driving

Even mild astigmatism can disrupt vision in low light. Proper correction not only restores clarity but also ensures confident night driving and long-term eye health.