A solar eclipse is a rare phenomenon that occurs when the moon passes between the Earth and the sun, partially or fully blocking the sun’s light for a few minutes. Although it is tempting, looking at an eclipse can cause eye problems.
Even briefly looking at intense sunlight can lead to eye damage, pain, and vision problems.
It is always best to avoid viewing a solar eclipse without proper eye protection, as this may cause issues such as “eclipse blindness” or even destroy cells in the back of the eye.
This article will explain the causes of dry eyes or eye pain following an eclipse, further symptoms of eye damage, and the treatment options available.
Exposure to direct, intense sunlight can cause damage to the outer layer of the eye. This transparent outer layer is the cornea, and damage to this tissue can lead to a condition called solar keratitis, also known as UV keratitis. It causes burning pain or discomfort in the eyes.
Staring directly at an eclipse may also damage the retina, a structure of light-sensitive tissue at the back of the eye. Doctors call this solar retinopathy.
The retina’s role is to send light via the eye to the brain as visual information, which the brain processes, allowing people to see. Intense exposure to sunlight can damage cells in this tissue and cause pain and problems with a person’s vision.
Tips from NASA on how to view a solar eclipse safely
- Only look at it through safe solar viewing glasses.
- Make sure they comply with the ISO 12312-2 standard.
- Do not use solar viewing glasses that are torn, scratched, or damaged.
- Do not look at the sun through a camera lens.
- Consider using an indirect viewing method instead.
- View the eclipse when the moon completely obscures the entirety of the sun.
If direct viewing of an eclipse has damaged a person’s cornea, it may take a few hours or days to have symptoms.
Symptoms of solar keratitis may include:
- eye pain
- feeling like a foreign body is stuck in the eye
- slightly decreased vision
- excess tear production
- light sensitivity
Damage to the retina from looking directly at the sun will typically cause symptoms a few hours after the event. These are usually present in both eyes. However, they may be worse in a person’s dominant eye.
Symptoms of solar retinopathy can include:
- blurred vision
- a blind spot in the center or near the center of the vision
- atypical color perception, known as chromatopsia
- headache in the front of the head
- light sensitivity
- seeing objects as distorted, known as metamorphopsia
- seeing objects as smaller than they are, known as micropsia
In some cases, damage to the retina may cause no symptoms, and a doctor may first notice it during a routine eye examination.
The main risk factor for eye damage while viewing an eclipse is looking directly at the sun without protective equipment. Although the front of the eye can protect against and absorb a certain amount of sunlight, too much intense exposure can cause damage.
Due to the intensity of the sun’s rays, research suggests that staring at it directly for even 10 seconds can cause damage. The risk increases the longer a person stares at the sun.
Damage to the eyes can occur to anyone who views direct sunlight. However, the following factors may increase a person’s risk of solar retinopathy:
- being of a young age
- being on medications that can damage parts of the eye, such as hydroxychloroquine (Plaquenil)
- being on medications that can cause the eyes to become more sensitive to light, such as tetracyclines, a type of antibiotic, and psoralens, a medication that treats skin conditions such as eczema and psoriasis
- psychiatric conditions such as schizophrenia
If a person has any concerns about their eyes after viewing an eclipse, it is best to visit an eye doctor, optometrist, or ophthalmologist, who can assess the extent and location of any damage.
Damage to the outer layer of the eye will tend to heal on its own within 72 hours. Treatment aims to help this healing process and may involve:
- topical ointment
- artificial tears
- topical nonsteroidal anti-inflammatory drugs
- pain medication
- topical antibiotics to prevent infection
- avoiding wearing contact lenses for a certain amount of time to allow the eye to heal
- using cool compresses on the eyes
If a person experiences damage to their retina after viewing an eclipse, treatment and management typically involve waiting for the retina to heal.
For many people, their usual vision will return within 6 months. However, vision changes, such as blind spots and distortion still present after this will likely be permanent.
It is always necessary to use protective equipment when viewing an eclipse.
A person may experience dry eyes if they have looked at the sun without appropriate protection. If a person experiences dry eyes or eye discomfort after looking at an eclipse, it is best to contact an eye doctor.
They may recommend treatments such as ointments or eye drops to help heal any damage after viewing an eclipse. Although many cases will resolve on their own, some people may experience permanent changes to their vision.