Hazy Winter Sun Can Still Damage Your Eyes: Why You Should Not Ditch Your Sunglasses

The winter sun in North India may feel gentle, with a pale sky, hazy mornings, and less intense sunlight. As temperatures drop, many people put their sunglasses away, assuming that cloudy weather means less risk to their eyes. However, this assumption can be misleading.

Ultraviolet (UV) radiation is present even when the sun does not appear particularly bright. Some UV rays can pass through cloud cover and reach your eyes, making protection important even during winter. Prolonged exposure can increase the risk of eye damage, including cataracts and other eye conditions.

For more insights, we spoke to Dr Shibal Bhartiya, Clinical Director – Ophthalmology at Marengo Asia Hospitals, Gurugram and Dr Sharad Kumar Mishra, General Ophthalmology, Sankara Eye Hospital, Kanpur.

Why Can Hazy Winter Sun Harm Your Eyes?

UV radiation is an invisible part of sunlight that can affect different structures of the eye, including the cornea, conjunctiva, and lens. According to eye-health estimates published in the International Journal of Molecular Sciences, up to 80% of UV radiation can pass through thin cloud cover.

This means a dull or hazy sky does not necessarily indicate low UV exposure. The risk also depends on factors such as the time of day, location, altitude, and surrounding environment.

Snow can increase exposure further because it reflects UV radiation. Fresh snow can reflect up to 80% of UV rays back towards your face, compared with around 15% reflected by dry sand. Therefore, people travelling to hill stations during winter need to be particularly careful.

What Can UV Exposure Do to Your Eyes?

Repeated or excessive exposure to UV radiation can affect eye health in several ways.

Photokeratitis
Often described as a sunburn of the eye, photokeratitis occurs when UV radiation damages the cornea, the clear front surface of the eye. It can cause pain, redness, excessive watering, a gritty sensation, and sensitivity to light.

Symptoms may not appear immediately. They can develop around six to 12 hours after exposure, sometimes becoming noticeable at night.

Also Read: Burning Eyes After Hours on Your Phone: Screen Strain or Dry Eye?

Cataracts
Long-term UV exposure can contribute to the development of cataracts, a condition in which the eye's natural lens becomes cloudy. This can cause blurred vision, glare, and difficulty seeing clearly.

Age-related macular degeneration
Long-term UV exposure may contribute to oxidative stress and damage to eye tissues. However, age-related macular degeneration (AMD) has several risk factors, and UV radiation is not established as its primary cause.

Pterygium
Pterygium is a fleshy growth that develops on the white part of the eye and may gradually extend towards the cornea. Long-term exposure to sunlight, particularly UV radiation, along with dust and dry wind, can increase the risk.

Can Winter Haze and Pollution Make Eye Irritation Worse?

According to a study published in the International Journal of Environmental Research and Public Health, winter haze and air pollution are separate from UV radiation, but both can affect eye comfort.

Dust, suspended particles, and pollutants can irritate the eye surface, causing redness, watering, itching, and discomfort. Cold air, low humidity, and wind can also increase tear evaporation, worsening dry-eye symptoms.

People who commute for long hours, ride two-wheelers, or work outdoors may experience greater irritation due to combined exposure to wind, dust, and pollution.

How to Protect Your Eyes During Winter

A few simple precautions can help reduce UV exposure and protect your eyes.

• Choose UV-protected sunglasses: Look for labels stating UV400 or 100% UVA and UVB protection. These indicate protection against both types of ultraviolet rays.
• Do not judge sunglasses by their colour: Dark contact lenses or expensive frames do not automatically offer UV protection. Dark lenses without a proper UV filter can be particularly harmful because they cause the pupils to dilate, potentially allowing more UV radiation into the eyes.
• Choose larger or wraparound frames: These help block UV rays entering from the sides.
• Wear a brimmed cap or hat: This provides additional protection by reducing direct sunlight reaching your eyes.
• Protect children's eyes: Children also need UV-protective sunglasses and hats, particularly during outdoor activities.
• Take extra care in the hills: Snow reflects UV rays, increasing exposure even when the sunlight feels mild.

Also Read: Flaky Eyelids in Changing Weather: When Is It More Than Just Dry Skin?

When Should You See an Eye Doctor?

If your eyes become painful, red, and watery after spending time outdoors, particularly after a trip to a snowy destination, do not rub them. Consult an ophthalmologist the same day to check for possible corneal damage.

Persistent redness, significant light sensitivity, eye pain, or blurred vision also warrants prompt medical evaluation. Sudden changes in vision require urgent medical attention.

Final Word

Winter sunlight may feel less intense, but UV radiation does not disappear with the arrival of cold weather. Wear UV400 sunglasses on bright winter days, during hill trips, and whenever you spend long hours outdoors. A hazy sky is not a substitute for eye protection.