Simply put, the eyeglass lens is a tool you use to focus light appropriately on your retina. For example, a lens that is concave, or curves inward, is used to correct nearsightedness, while a lens that is convex, or curves outward, is used to correct farsightedness.
Nearsightedness causes nearby objects to appear clear, while objects farther away look blurry. Farsightedness is where far away objects appear clear and objects up close appear blurry.
To correct astigmatism, which is caused by distortions in the shape of the cornea, a cylinder shaped lens is frequently used.
Horses have the largest eyes of any land mammal, and their side-placed eyes give them nearly 360-degree vision, with small blind spots directly in front and behind.
In 1858, a 14-year-old girl named Bernadette Soubirous reported visions of Mary at Lourdes, France, which became one of the world's most popular pilgrimage sites.
Our Lady of Guadalupe refers to visions of Mary reported by Juan Diego in Mexico in 1531, and her basilica in Mexico City is one of the most visited Catholic shrines in the world.