Snow blindness

Disease Description (Causes and Symptoms)

Snow blindness (photokeratitis) is a photokeratitis condition in which the corneal epithelium and conjunctiva are temporarily damaged by intense ultraviolet (UV) exposure. The main cause is exposure to UV rays reflected from snow surfaces, dazzling snow and ice surfaces, and direct sunlight at high altitudes or on clear days. Wearing contact lenses or not having protective eyewear increases the risk.
Main symptoms: eye pain (severe burning), redness, photophobia, tearing, a foreign-body sensation, difficulty opening the eyes, and decreased vision (temporary) — symptoms begin within several hours (usually 6–12 hours) after UV exposure and generally improve within 24–72 hours. In severe cases, an epithelial defect or opacity on the corneal surface may develop, and decreased vision may persist.

Treatment

• General principles: Stop exposure, block light (rest in a dark environment), and remove contact lenses immediately.
• Conservative treatment (most patients with mild to moderate disease):
  • Apply cold compresses and darken the environment (block light with sunglasses or an eye patch).
  • Artificial tears (preservative-free eye drops) may help.
  • Control pain with oral analgesics (e.g., NSAIDs).
  • If necessary, ophthalmic anti-inflammatory medication prescribed by a doctor (topical NSAIDs) or injectable analgesics.
  • For severe pain, a single-eye cycloplegic (mydriatic) may be used to relieve pain.
• Medication/procedure precautions:
  • Do not use topical anesthetics for self-administration (ophthalmic anesthetic eye drops), due to the risk of delayed corneal healing and worsening damage.
  • If a corneal epithelial defect is confirmed, topical antibiotics may be applied by an ophthalmologist to prevent secondary infection (as directed by a doctor).
  • Steroids may be used in some situations for noninfectious inflammation (at the doctor's discretion), but they are not generally the first choice.
• Indications for specialist referral:
  • Seek immediate ophthalmologic care if there is decreased vision, a central visual-field abnormality, corneal opacity/epithelial defect, worsening symptoms, or no improvement within 48–72 hours.
• Lifestyle management and precautions:
  • Do not rub the eyes during recovery and avoid contact with dust and contaminants.
  • Do not resume wearing contact lenses until complete recovery (as directed by a doctor).
  • Be aware of the possibility of complications such as secondary infection and corneal ulcers.

Checklist Before an Outpatient Visit (Including Sample Questions)

Items/records to prepare:

• List of medications currently being taken (especially anticoagulants, steroids, and immunosuppressants).
• Information about previous eye diseases (corneal disease, glaucoma, surgical history) and systemic diseases (such as diabetes).
• Time of symptom onset and progression (duration of exposure, time until the first symptoms appeared, and recorded changes in symptoms).
• Whether contact lenses were worn and the time they were last worn.
• Emergency measures taken at the site (rinsing with water, compresses, medications, etc.).
• Changes in vision (if possible, visual-acuity chart results or a description such as “my vision feels half as good”).
• Exposure environment (ski resort/ice surface/altitude/whether protective equipment was worn).

Items to tell the healthcare provider in advance during the outpatient visit:

• Time of symptom onset and factors that worsen or improve symptoms
• Whether there was recent exposure to animals, chemicals, or foreign bodies
• Whether there is fever or ocular discharge (purulent)

Examples of General Questions to Ask the Doctor

• "What exactly is causing these symptoms?"
• "What treatment do you recommend, and what is the expected recovery time?"
• "What are the side effects of the prescribed medication?"
• "When can I drive again or resume daily activities?"
• "What lifestyle habits or preventive measures can help prevent recurrence?"

Examples of Condition-Specific Questions

• "When did the symptoms begin after the exposure, and how did they change during the first 24 hours?" (Important for diagnosis and prognosis)
• "Were you wearing contact lenses? When did you last remove them?" (Important for management and infection-risk assessment)

Summary of Additional Precautions:

• It is generally temporary and improves with appropriate conservative treatment, but immediate ophthalmologic care is needed if there is decreased vision or corneal opacity.
• Prevention: Wear goggles/sunglasses with UV-blocking capability; in environments with intense light reflection (snowfields and ice surfaces), use goggles, hats, and broad-area coverage; protective equipment is recommended during outdoor activities.