Effects of Astigmatism on Night Vision and How to Manage It

Astigmatism is a vision condition caused by imperfection in the curvature of the eye that leads to distorted or blurred vision. It happens when the cornea or lens of the eye is not shaped normally, making it difficult for light to focus correctly on the retina. The cornea is a transparent curved layer of tissue that covers the front surface of the eye. It transfers light to the back of the eye and concentrates it there. In astigmatism, the cornea is often egg- or football-shaped and curves differently, causing the light to focus on two points on the retina instead of one. This results in decreased, blurry, and distorted vision. Astigmatism often occurs with near-sightedness or farsightedness, and can be managed through surgery or corrective lenses. Let’s discuss how astigmatism impacts night vision along with some useful advice and remedies to help you navigate dimly lit environments.

How Astigmatism Affects Night Vision

At night or in other low-light conditions, our pupil dilates to let more light into our eyes for seeing better. This exacerbates the symptoms of astigmatism and may increase the blurring and night glares. Astigmatism can cause glares or halos around headlights or street lights. This can be confusing, disconcerting, and even quite dangerous when driving at night.

 

 

Symptoms of Astigmatism & Its Effect on Night Vision

 

 Common symptoms of astigmatism are as follows: 

• Blurred or distorted vision
• Discomfort and eye strain, especially when needs to focus for long periods
• Headaches
• Irritated eyes
• Diminished night vision or difficulty in driving at night
• Squinting to see clearly
  
  

The Effect of Astigmatism on Night Vision
Astigmatism generally causes the following consequences:

 

• Glares or fuzzy beams of light.
• Beams of light or glares caused by the cars' headlights.
• Vision-related issues due to rain.
• Fuzzy lights or other objects may look blurry.
• Halos could be visible in the vicinity of the light source.

Causes and Risk Factors of Astigmatism

The exact cause of astigmatism is unknown. Some people are born with astigmatism, but many people develop it as children or young adults. Common causes are:

• Usually present from birth, hereditary (passed down from parents).
• May develop after an eye surgery or eye injury.
• Result of keratoconus, a very uncommon disorder in which the cornea gradually thins and takes on a cone shape.
  
  

How do you know if you have astigmatism?

Most people find out they have astigmatism after receiving a prescription for glasses from an eye doctor. Hence, the best way to find out if you have astigmatism is to go for a comprehensive eye exam at your eye doctor’s office. The exam includes a visual acuity test (reading letters on a distance chart), keratometry (to measure the curvature of the cornea), and a refraction test (to check your lens focus).

 

Treatment of Astigmatism

If the astigmatism is mild, the doctor may recommend no treatment at all. Otherwise, corrective lenses are the standard solution, although some Individuals may prefer to opt for laser surgery. Current treatment trends are as follows:

 

1)      Corrective lenses: These lenses aid in accurately projecting images onto the retina. These could come in the shape of contact lenses or glasses.

Astigmatic lenses require:

 

• The ability to adjust near or farsightedness with a spherical power
• A cylinder lens power to rectify astigmatism
• An axis designation that indicates where the astigmatism is located
• A person with presbyopia will need more power in their lenses to correct this condition.
  
  

2)      Orthokeratology, or corneal refractive therapy: In orthokeratology, the cornea is reshaped while you sleep by using a hard contact lens that is custom-fitted. This does not offer a permanent improvement, but the wearer may notice that their vision improves for at least a few hours after using it.

3)      Laser eye surgery (LASIK): Your cornea is reshaped during laser eye surgery (LASIK or PRK) to improve light ray focus. After administering eye medications to numb the area, the surgeon creates a thin flap on your cornea using a laser. Your cornea's core layers are exposed, and a laser is used to shape them. Subsequently, they put the flap back in place. Lastly, they offer you eye drops that are both antibiotic and anti-inflammatory. You can leave for home once they have placed translucent shields over your eyes.

4)      Remove cataracts: Both cataract (clouding in the eye lens) and astigmatism affect your night vision and double your trouble while driving at night. Cataract surgery involves removing cloudy lenses, replacing them with clear, synthetic ones. 

5)      Use anti-glare night driving glasses: You can buy over-the-counter anti-glare glasses designed exclusively for night driving. These glasses have yellow lenses that filter blue light to lessen glare. Additionally, some glasses also have an anti-reflective coating.

Astigmatism occurs when the cornea has an irregular shape that distorts light, causing blurriness in the vision that especially affects your night vision. In astigmatism, it is common to see halos around lights while driving at night. Astigmatism can typically be effectively treated with contact lenses, spectacles and surgery. It's possible that many people with astigmatism are unaware of their condition but astigmatism may worsen over time. Hence, it is pivotal to consult your ophthalmologist and get routine eye exams.

Ask a Doctor, facilitates online consultation-24x7, you can send your astigmatism related questions to ophthalmologists, and they will reply within minutes. You can also send in your other eye related questions to Ask a Specialist on all health related matters. Ask now!