Toplens Hangzhou [中文]
SOCIALIZE WITH US:
Toplens Hangzhou Inc.
Bldg 7/1F, 1197 Bin'an Road,
Binjiang, Hangzhou, Zhejiang,
310052 China
TEL：+86 571 8777 4064
FAX：+86 571 8777 4033
info@toplens.cn
Personalized custom design will collect parameters of each user's frame face form angle(wrap angle), pupil distance, pantoscopic tilt angle, Cornea Vertex Distance(CVD) to optimize the design of the lens surface to make the wearer have a clear view in different direction for each eye to improve wearing comfort. Its essence is to calculate the wear optical power of lens surface.
How to calculate wearing power? According to definition of wearing power, we assume a bundle of parallel light ray entering a spectacle lens, the eye's center of rotation, on far point sphere, which is the sphere that eye can see clear without lens. The point to calculate wearing power is to define direction and position of incident principal way.
According to the principle that path of light is reversible, direction of incident principal ray can be obtained by reversing outgoing light rays through the eyeball center of rotation, then finding the point of convergence of light beams on the far point sphere (the tangential and sagittal image points), calculating the distance from the convergence point to the center of rotation of the eyeball, minus the radius of the Vertex Sphere, and the reciprocal of remaining distance is the wearing power. In general, when human eyes look in different directions through lens, wearing power of the lens is variable. Mostly the variance in both oblique astigmatism and power is the reason causing human eyes unable to view things on their sides clearly without moving their heads.
Free4D ray tracing software comes with power compensation function, and can be personalized to enable human eyes to view very clearly in the range of 360 degrees.
