The August 21st 2017 Solar Eclipse was certainly an exciting piece of history to be a part of. Unfortunately, some people who did not take the correct safety precautions may become afflicted with ‘eclipse blindness’ or solar retinopathy.
The retina is the innermost layer of the eye and is comprised of nerves that sense the incoming source of light. This network of nerves sends impulses to the optic nerve which are transmitted to the brain and then translated to images that we can see. One layer of the retina contains tiny photoreceptor cells called rods and cones.
Exposure of the retina to intense visible light causes damage to the rod and cone cells. The light triggers a series of complex chemical reactions within the cells that damages their ability to respond to a visual stimulus and in extreme cases, can destroy them.
The result is a loss of visual
function, which may be either temporary or permanent depending on the severity of the damage.
When a person looks repeatedly, or for a long time at the Sun without proper eye protection, this photochemical retinal damage may be also be accompanied by a thermal injury.
The radiation that is not absorbed by the photoreceptors is absorbed by the retinal pigmented epithelium where it is transformed into heat that literally cooks the exposed tissue.
This thermal injury or photocoagulation destroys the rods and cones, creating a small blind area. This danger to vision is very serious because photic retinal injuries occur without any feeling of pain (the retina has no pain receptors) and the visual effects may not become apparent until several hours after the damage is done.
Note that this thermal injury does not result from exposing the retina to solar infrared (IR)
radiation. Intense IR radiation can also cause thermal injury to the retina, but during solar observations the main thermal hazard is prolonged, unprotected exposure to visible light.
Signs and Symptoms of Solar Retinopathy
- Reduced visual acuity (bad vision),
- Central scotomas (blind spots),
- Chromatopsia (disruption or tinting of color perception),
- Metamorphosia (disruption or distortion of shape perception), and
- Photophobia (light sensitivity)
If you are experiencing any of the above symptoms after viewing the 2017 Solar Eclipse and they have not resolved in a day or two, please call (805) 364-5448 to schedule an examination with Dr Jacobson.