Difference between Spherical Lens and Aspherical Lens

Generally speaking, spherical lenses are thick and the images through the lenses will be distorted. While, with the same prescription and index, aspherical lenses are thinner, lighter, and more comfortable for wearers. Aspherical lenses have a wider vision and the images through the lenses are more real and natural. Wearers will not feel tired after wearing aspherical lenses for a long time.