Looking at a solar eclipse without proper eye protection can cause serious damage to your eyes, including "eclipse blindness" or retinal burns, which can cause temporary or permanent vision impairment, and in worst-case scenarios can lead to legal blindness. The retina, which is the back of the eye that transmits what you see to the brain, can be damaged or even destroyed by the exposure to the light. The damage can be temporary or permanent and occurs with no pain, and it can take a few hours to a few days after viewing the solar eclipse to realize the damage that has occurred. Symptoms include loss of central vision, distorted vision, and altered color vision. If you notice symptoms after viewing a solar eclipse, seek treatment from an eye care professional immediately.

It is never safe to look at a partial solar eclipse without proper safety equipment or techniques. During the very brief time the sun is in total solar eclipse, it is safe to look at it, but do so with caution. Even during the total solar eclipse, the total eclipse phase lasts only a few minutes, so it is still recommended to use proper eye protection. The only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters, such as "eclipse glasses" that meet the current international standard for eye protection. Other safe ways to view a solar eclipse include making a pinhole projection or using number 14 welder’s glasses.

In summary, it is crucial to protect your eyes during a solar eclipse to avoid serious and permanent damage to your vision.