Rainbows are beautiful, but seeing them at nighttime may be a cause for concern.

Often referred to as “rainbow vision,” seeing rainbow halos around lights is a normal response to bright lights. But it can also indicate an eye and vision problem with how light is filtering into the eye and is something to bring to the attention of your Toronto eye doctor.

Light is made up of different colors, but because the rays focus on a single point, you can’t distinguish them. Thus, when you see halos around lights, it may mean that scattering of light is occurring in the cornea or lens of the eye.

What Causes Rainbow Halos Around Lights?

Colorful lights in your line of vision are caused by a variety of different factors.

This symptom is common after sustained bright sunlight exposure, or even from camera flashes. In these cases, the problem is usually temporary and resolves on its own within a few hours or up to two days.

Other causes may include:

Cataracts: Normally, the lens at the front of the eye is clear, allowing light to easily pass through. A cataract clouds the lens, which blurs the vision and affects the way your eyes take in light. Halos and sensitivity to lights at night are common symptoms of cataracts.

Diabetes: Over time, too much sugar in the blood can damage the blood vessels and nerves in your eyes, making you more likely to have night vision problems.

Retinitis pigmentosa: This rare genetic disorder causes a breakdown and loss of cells in the retina. Difficulty seeing at night is one of the earliest symptoms.

Eye Procedures: Eye procedures such as Radial Keratotomy, Penetrating Keratoplasty, or laser procedures such as LASIK may cause night vision problems, including rainbow vision.

Common eye problems: Common eye conditions may be to blame for the rainbow halos you see around lights.

Eye conditions that can cause rainbow vision include:

• Nearsightedness – hard to see things far away
• Farsightedness – hard to see things up close due to the shape of your eye
• Presbyopia – farsightedness due to aging
• Astigmatism – blurry vision due to the irregular shape of the cornea or lens of the eye

Nutritional deficiency: Both vitamin A and zinc deficiency have been linked to problems in night vision. To get your vitamin A, eat lots of carrots and leafy greens. Great sources of zinc include red meat, seafood, poultry, eggs, nuts, and beans.

Video Source: Canadian Association of Optometrists

How Do I Treat Rainbow Vision?

There are some simple steps you can take to protect your eyes. Wear sunglasses during the day, use your vehicle’s visor to keep direct sunlight out of your eyes, and keep the flash off of your camera.

While these steps can help, they are not a cure. It’s important to consult your Toronto optometrist should you experience any of these symptoms.

Along with rainbows and halos disrupting your eyesight, if you experience sudden blurry vision and eye pain, seek medical attention immediately. This symptom could be an indicator of an episode of glaucoma, which can cause blindness if not treated.