Spherical lens VS Aspherical lens
Spherical lens VS Aspherical lens
When the eye sees something through the center and periphery of the spherical lens, the light from the center and the edge cannot concentrate the image on one point, which causes the image to be refracted and distorted, which affects the clarity of the field of view.
The design of aspheric lenses can improve these phenomena. It changes the surface curvature of the lens so that the light from the center and the edges are concentrated at the same point, and the field of view will be clearer.
The curvature of the aspheric lens varies from center to edge. The surface is not "a circle" and cannot be stretched to form a sphere on the left and right. Because the curvature is changed, under the same degree, the side of the aspheric lens will be thinner than the spherical lens, which has a better wearing experience.
The optical design of spherical lens and aspherical lens is different. If you wear open spherical lens and then turn to aspherical lens, you will feel a little dizzy at the beginning of wearing, and vice versa.
Most of the four-eyes in Hong Kong have used aspherical lenses. Some fast-fashion eyewear companies on the market sell eyeglass frames and send lenses "for free", and most of these "free" lenses are spherical lenses. If you visit fast fashion eyewear companies and only use "free" lenses, it is easy to get dizzy at first. The long-term experience is not good.
Spheric lens is a design type of lens. Different brands of aspheric lens have different designs and performance.
bi-Aspherical Lens
Adding an aspheric design to one of the lenses can greatly improve the optical quality. In order to further improve the imaging and edge thickness of the lens, the manufacturer developed a double-sided aspheric design. Design and manufacture are more difficult, and bring a better wearing experience.
Reduce appearance impact
The depth of the lens will enlarge or reduce the image behind the lens. The eyes and face of the wearer appear to be partially enlarged or reduced. Aspheric lenses can reduce this appearance impact.
