The sun is incredibly bright and directly looking at it for anything longer than a few seconds can result in damage to the back of the eye.
It is imperative to use the proper glasses or viewers during a partial or total eclipse of the sun. Only for the few minutes when the sun is completely covered can eclipse glasses can be safely removed. This will only occur in the path of totality, and not in the states of Jalisco, Colima or Nayarit, where only a partial eclipse will be visible on April 8.
Special glasses or viewers must be used whenever the disk of the sun itself can be seen. You should never use sunglasses of any kind, color film, medical X-ray film or smoked glass.
Watchers should avoid looking through a camera, telescope or a pair of binoculars that haven’t been treated with a filter even while wearing eclipse glasses. The sun’s rays can pass through lenses used by those devices and melt the filters that the glasses are using to protect your eyes.
The only safe way to watch a solar eclipse without a filter is by turning your back to the sun and watching a projection.
Various certified eclipse glasses are available on Amazon, with prices ranging from 150 to 500 pesos.