Face bend is the curvature of the cheap eyeglasses near my frame, which can be understood as the angle between two lenses, while base bend is the curvature of the surface of one lens.

When encountering large curved frames, large base curved lenses are generally used in the processing of glasses. Otherwise, insufficient curvature of the lenses will flatten the frame, causing the assembled cheap eyeglasses near me to have smaller surface curvature and lose their original shape. At the same time, due to the mismatch between the curvature of the lens and the frame, the lens is prone to pop out and fall off during use.

One of the characteristics of nonspherical lenses is that they are flat. If you want a large base curvature, it is best to choose spherical lenses. Nonspherical lenses generally have a maximum curvature that can meet most frames.

Under the same degree, the higher the refractive index, the thinner the lens. Myopia lenses are concave lenses with a thin edge in the middle. So the larger the frame size, the thicker the edge of the lens.

The greater the difference between the pupil distance and the geometric center of the frame, the thicker the edge of the lens. So, the closer the sum of frame sizes is to the pupil distance, the thinner the edge of the lens.

Some manufacturers on eyeglass mart accept incoming board dyeing, which means they can dye according to the color specified by the customer. Due to the inability to quantify colors, factors such as lens thickness, viewing angle, and film color often have a strong subjectivity in color judgment. Therefore, when dyeing the board, it is important to emphasize to customers that there may be a color difference between the finished product and the sample.