It is harmful for the eyes if you stare at the bright light for a long time with no care for the eyes. Although you may say that the distance is far away, the strong sun light will emit the strong heat energy. And it is possible for the eyes to get blindness if you stare at the bright light for continuous time. Our lens in the eyes is similar to the convex lens. If you stare at the light resource, especially the high heat of sun, the most serious consequence of your eyes is that the retinal gets burned. After that, you will find that you see things with the black hole in your vision focus. That is very bad which means that your retinal is damaged. If you don't get the immediate treatment, you will get blindness. Thus, you'd better wear the sunglasses with the special coating at the lenses which will protect your eyes from the uv and other strong lights.