Why Do Stars Seem To Have 5 Points (Corners)?

When light emitted from a distant object reaches another object or opening, its waves are bounced or bent slightly around the object and interfere with each other to produce various patterns on whatever they ultimately fall on. For example, light passing through a slab with a tiny slit leaves its imprint in the form of a perpendicular series of dashes. This is the reason why any light source appears to sparkle with pointed corners when you squint your eyes.

However, this only covers one part of the explanation. The other part has to do with our eyes, or rather, certain imperfections in our eyes.

The fibers that make up our eye lenses meet at certain points, resulting in very small structural imperfections called suture lines. Light, upon passing through the lens, interacts with these lines and consequently leaves a very distinct impression of a star, making it look like a pointy, five-armed toy.