Generally speaking, the spherical lens is thicker; the imaging through the spherical lens will deform.
The aspheric lens, is thinner and lighter, and make a more natural and realistic image.
Scratches on lenses are distracting,
unsightly and in certain conditions even potentially dangerous.
They can also interfere with the desired performance of your lenses.
Scratch-resistant treatments toughen up the lenses making them more durable.
For fashion, comfort and clarity, anti-reflective treatments are the way to go.
They make the lens nearly invisible, and help cut glare from headlights, computer screens and harsh lighting.
AR can enhance the performance and appearance of just about any lenses!