Coma is a type of lens aberration that causes asymmetrical distortion of point light sources, often making them appear comet-like with streaks radiating outward. It is most noticeable in night photography or when shooting bright points of light, especially near the edges of an image. Coma can affect image sharpness and overall quality, but it can be minimized by using high-quality lenses, stopping down the aperture, or correcting digitally in post-processing. Understanding and managing coma is important for photographers aiming for precise optical performance and clean, distortion-free images.