An optical lens is an optical element used to control the propagation and focusing of light. They are widely used in various optical systems, including photography, telescopes, microscopes, lasers, fiber optic communication, etc. Here are some common optical lens products:

1. Convex lens (positive lens): A convex lens is a lens with a thinner center and gradually thicker sides. They focus light outward and are often used in optical systems to magnify and focus images. Convex lenses can be used to correct myopia and are commonly used in equipment such as camera lenses and glasses.

2. Concave lens (negative lens): A concave lens is a lens with a thicker central thickness and gradually thinning on both sides. They disperse light and are used in optical systems for defocusing, correcting eye refractive errors, and more. Concave lenses can also be used for refracting telescopes, microscopes, and other devices.

3. Double convex lens: A double convex lens is a combination of two identical convex lens faces facing each other. They have stronger focusing ability and smaller astigmatism. Double convex lenses are commonly used in imaging optical systems, such as camera lenses and telescopes.

4. Double concave lens: A double concave lens is a combination of two identical concave transparent mirrors facing each other. They make light more dispersed and are commonly used for achieving specific optical effects, such as broadening the imaging field of view and making myopia glasses.

5. Fish eye lens: Fish eye lens is a specially designed wide-angle lens with a very wide field of view angle. They typically produce distorted images, but are also widely used in wide-angle photography, visual effects, and monitoring systems.

In addition to the common optical lens products mentioned above, there are many other types and specially designed lenses available for selection to meet various application needs. The selection of lens materials, lens shape and curvature, and other factors can all affect the optical performance and application effect of lenses.