Solar eclipse

A solar eclipse occurs when the Moon passes between the Earth and the Sun and casts its shadow on the Earth, so that it seems that night has fallen for a few minutes. For a solar eclipse to be total, the Earth, Moon and Sun must be perfectly aligned. This phenomenon is very rare and lasts only a few minutes.

Hazards associated with solar eclipses

As with the sun or any source of bright light, you must avoid looking directly at a solar eclipse without protection. When a person watches a solar eclipse without eye protection, they are exposed to hazards that can have consequences on their vision, such as:

• damage to the cells of the retina, called “solar retinopathy”
• temporary loss of vision (blurred vision, altered colour perception)
• partial or total blindness

The effects may go unnoticed at the time and appear several hours or even a few days after watching the eclipse. It only takes a few seconds for irreversible damage to occur.

Furthermore, due to the exceptional nature of the phenomenon, the risk of being distracted is higher than usual. Greater vigilance is required, especially for outdoor workers and drivers.

Recommended preventive measures

During a solar eclipse, it is recommended to:

• encourage work indoors
• avoid looking directly at the eclipse without suitable eye protection during all the phases
  • Workers who must look up at the sky are advised to keep the sun out of their field of vision (face away from the sun).
• avoid viewing or photographing the sky through a lens (binoculars, telescope, etc.) without a special purpose solar filter
  • Activities with this type of equipment should be postponed until after the eclipse to limit the risks.

Important

If, in the course of their work, a worker must look up at the sun during the solar eclipse, it is strongly recommended to wear glasses with ISO 12312 2–certified lens filters for the entire duration of the eclipse and to make sure they are in good condition (no damage to the frame or lens).

These glasses should not be worn for other tasks, such as driving a vehicle. When driving a vehicle, a sun visor can be used to avoid the risk of accidental observation.

Appropriate eye protection

Appropriate eye protection must be worn for the entire duration of an eclipse. Only a few seconds of unprotected direct observation are enough to cause irreversible damage when the sun’s rays are visible.

Only glasses with ISO 12312 2–certified lens filters and a special purpose solar filter for optical devices (binoculars, theodolite, telescope, etc.) provide adequate eye protection. In addition, the filters must be in good condition (no damage to the lens) to maintain their protective effect.

In you do not have a solar filter or cannot wear glasses with certified lens filters, it is recommended to postpone tasks where the sun is in your field of vision until after the eclipse in order to limit the risks.

Because of their obscuring power, glasses with ISO 12312-2-certified filter lenses should only be used for direct observation of the eclipse. They must not be worn for any other purpose, including driving. When driving, a sun visor can be used to avoid the risk of accidental observation.

First aid in the event of direct exposure to radiation

If a person has directly observed the eclipse without eye protection, they should consult an ophthalmologist or optometrist as soon as possible.

If the person has severe symptoms, a call can be made to Info santé 811 to be referred to the appropriate medical services based on the symptoms observed.