Eclipse glasses are simple to use, but they are safety equipment and should be checked before every viewing session. A quick inspection takes less than a minute and helps you spot damage that could make a viewer unsuitable for direct solar observation.
1. Confirm that they are proper solar viewers
Use special-purpose eclipse glasses or a handheld solar viewer intended for direct observation of the Sun without magnification. The product documentation should show conformity with ISO 12312-2:2015 and include clear manufacturer instructions. Ordinary sunglasses, smoked glass, exposed film and improvised filters are not substitutes, no matter how dark they appear.
2. Examine the filter in good indoor light
Hold the glasses by the frame and inspect the filter from both sides. Look carefully for scratches, tears, punctures, holes, deep creases, peeling layers or any area where the filter is separating from the frame. If you find damage, or if you are uncertain about the condition of the filter, do not use the glasses. Do not try to repair a damaged viewing area with tape, glue or another transparent material.
3. Check the frame and fit
Make sure the filter is securely attached and that the frame is not split, badly bent or weakened. The glasses should stay comfortably in place and fully cover both eyes. If you normally wear prescription glasses, keep them on and place the eclipse glasses over them.
4. Read the supplied instructions
Follow the manufacturer’s directions, warnings, age guidance and storage advice. An ISO reference printed on a frame is not, by itself, proof of safety; reliable sourcing, traceable product information and appropriate testing documentation also matter. Always supervise children and confirm that their viewers fit correctly.
5. Put them on before looking up
Stand still, face away from the Sun and put the glasses on before turning toward it. When you have finished viewing, turn away before removing them. Stop immediately if the view seems unusually bright, the filter slips, or you feel discomfort.
6. Never combine eclipse glasses with magnifying optics
Do not look through binoculars, telescopes or cameras while wearing eclipse glasses or holding a viewer in front of your eyes. Concentrated sunlight can damage the viewer and cause serious injury. Optical equipment requires a suitable solar filter mounted securely over the front aperture, selected and used according to specialist and manufacturer instructions.
After viewing
Store the glasses flat in a clean, dry protective sleeve, away from sharp objects, heat and pressure. Inspect them again before their next use. If there is any doubt, replace them rather than taking a risk.