In a sea of snow pile snowmen, snowball fighting, skiing, enjoy the snowy white after the heavy snowfall is what most people aspire to, especially those who live in places where the temperature is higher without snow. But also pay attention to eye protection and be wary of snow blindness.
"Snow blindness, also known as electrophthalmia and ultraviolet eye injury, is damage to the conjunctiva and cornea of the eye caused by excessive exposure to ultraviolet light. The disease was first recognized as a result of damage to the unprotected eye caused by the intense ultraviolet light reflected from snow during prolonged walking in the snow, which can lead to temporary blindness in severe cases.
The white new snow surface of the sun's reflectivity is up to 95%. This time the snow surface of the light is close to the sun; looking directly at the snow surface is equivalent to looking directly at the sun; the eye is a transparent medium when the light is strong enough to penetrate the cornea, lens, vitreous body directly to the retina, causing direct damage to the eye.
Symptoms of snow blindness generally include tearing, redness, pain, pins and needles, sandy sensation, painful seeing, headache, loss of vision, blurred sense, and transient blindness.
Polar bears have adjustable pupils, and when the external light is intense, their pupils are adjusted very small to prevent excessive sunlight from stimulating the retina.
To avoid snow blindness, the Inuit wear oval wooden glasses with a small slit in the middle to prevent their eyes from stabbing, but the range of vision is limited to a few meters in front of them, so they can't help but stumble when walking.
In addition to the intuitive pain associated with corneal damage, snow blindness can also cause damage to the fundus of the eye. However, unlike corneal injury, fundus damage does not show apparent symptoms quickly, and it usually takes 2-3 days or more for the macular edema to gradually become larger and affect vision. Generally speaking, mild edema can subside with metabolism and restore vision. Severe edema gradually decreases in pain after the treatment. However, it still leaves irreversible damage and causes sequelae - disappearing to appear as a fixed, unchanging black spot in the visual field.
If snow blindness occurs outdoors, once symptoms and pain appear, promptly withdraw to a dark place and then carry out emergency treatment. - Check the eye condition; check whether there is no foreign body in the eye and whether there is mechanical damage. If wearing contact lenses, promptly remove them.
