Shopping for eyeglasses can be a time-consuming process complicated by the strange series of three numbers found on the frame temple (50-18-130, for example). The first number represents lens size, and understanding it completely can make your choice easier.
Shopping
The best way to get an excellent frame fit when shopping for glasses is to visit an optical boutique and have a trained professional assist you. Of course, going in armed with the knowledge of lens sizes will make the process that much easier.
Lens Numbering
The first number in the series represents the lens size, the second is the bridge size, and the third is the temple size. According to Optometrist Dr. Burt Dubow, frames vary by their shapes and sizes, so no set of numbers will apply to one person for every frame.
Naming
Lens size is also known as eye size or lens width. Lens width is the most accurate naming because it is the measurement of the distance between vertical sides of the frame. Therefore, lens height is not the same as lens size, and not included in the three number measurements. Lens size typically ranges from 44 to 52. Rarely, for bigger or taller people the size can extend up to 58.