Watching a solar eclipse is a special event for people of all ages and in all areas of the world. Whether it is a full or partial eclipse, seeing part or all of the sun seem to disappear from the sky is an amazing event, but there are some safety concerns involved in the activity. Using solar filters or eclipse glasses is a must for many different reasons.
Sunglasses are not Solar Filters
One of the most common mistakes that people make is to assume that sunglasses, particularly the very dark sunglasses, have the UV, infrared and visible light blocking ability to keep your eyes safe. This is a very serious error as these types of glasses, regardless of how expensive they may be, were never designed to look directly at the sun.
While sunglasses may offer very high levels of UV and infrared protection, that is only for reflected light that is typical in the world around you. However, specific solar filters glasses designed for eclipse watching provide full protection, including 100% ultraviolet light filtering, 100% harmful infrared blocking, and up to 99.999% blocking of intense visible light.
The Difference
If you wish to see the difference yourself, buy a pair of solar filters specifically designed for eclipse watching. These are often very low cost and resemble 3D glasses you may have used at your local movie theater or for home use with a 3D system.
Go outdoors on a bright sunny day and put on your sunglasses. Do not look at the sun, but look at a distant location with the sunglasses on. You will be able to clearly see images and details; there will just be the slight tint of the glasses.
Then, take off the sunglasses and put on the solar filters. You will immediately notice the difference as everything will be much darker but you will still be able to see some details, and there should be no distortion. This is the difference in protection levels, and sunglasses are obviously not able to provide the same filtering of the light that is so harmful to incorrectly protected or unprotected eyes looking up at a full or partial eclipse.
However, and this is the essential consideration to keep in mind, it is not the visible light that is so damaging to your eyes. With solar filters the UV and infrared light is fully blocked, allowing you to enjoy the experience without any worries about your eyes.