Solar eclipse and health

Direct viewing of a full or partial solar eclipse can cause permanent eye damage. ARPANSA recommends viewing an eclipse using indirect methods.

Eye safety and solar eclipses

Solar Eclipse Image A solar eclipse occurs when the moon passes between the sun and the earth, and the moon fully or partially obscures the sun. It is extremely dangerous to look directly at the sun even during a solar eclipse. You should never attempt to observe a total, partial or annular eclipse with the naked eye.

The safest technique for viewing a solar eclipse is indirect viewing. For example you can easily project an image of the sun onto a screen or you can view live streams on TV or online. Children's eyes in particular are extremely delicate and transmit more light through to the retina.This makes children’s eyes are more susceptible to damage from intense light.

The use of eyewear marketed as 'eclipse glasses' has become more popular. Safe use of these glasses relies on the filtering ability of the lenses and the design of the frames. Even where the lenses are certified to meet the applicable standards, improper use of these glasses may still result in serious eye damage.

ARPANSA recommends that solar eclipse glasses should not be used to directly view a solar eclipse.

Things to remember

  • Viewing the eclipse can cause permanent visual loss.
  • Damage occurs rapidly without any pain.
  • Loss of vision does not occur until after the eclipse.
  • There is no treatment and children are especially at risk.
  • ARPANSA advises against any direct viewing of the eclipse.

Sunlight

The main hazards to the eye from very intense sunlight are from heat (infrared radiation), UVR (ultraviolet radiation) and from excessive visible light, especially blue light. Even a momentary glance at the sun can focus a very intense amount of heat onto the back of the eye (retina). UVR can cause 'sunburn' to the outer surface of the eye (cornea). The least understood risk is from blue light which may also cause damage to the eye through photochemical retinopathy. 

Is it safe to look at a solar eclipse?

Normally the sun is so intense that it is difficult and very dangerous to look at it directly. Looking at the intense light from the sun even for just a few seconds can cause permanent damage to the retina (part of the eye directly responsible for vision). The retina has no sensitivity to pain, and since the effects of retinal damage may not appear for hours, there is no warning that an injury to your eye has occurred. The amount of time looking at the sun that will cause loss of sight varies from eye to eye but in all cases is only a matter of seconds. During a total solar eclipse so much of the sun is covered that a person may be tempted to stare at it directly. It is possible to suffer serious and permanent eye damage by looking at any type of solar eclipse and there is no treatment. Children are especially at risk due to more light reaching the retina than adults. 

Indirect viewing of a solar eclipse

The safest way of viewing a solar eclipse is to use indirect methods.

For further information on eye safety and indirect viewing methods, refer to the following released on solar eclipses from the Australian Society of Ophthalmologists.

References