An optical defect in a lens resulting in different wavelengths of light focusing at different distances from the lens, which can be seen as halos around the image.
SPHERICAL VS. ASPHERIC LENSES
HOW THEY’RE USED IN IMAGING APPLICATIONS
Optical Lenses are often categorized by their shape. Two common surface shapes are spherical and aspherical. Each offers unique characteristics that make it suitable for different use cases.