Optician Shares Video Cutting Extremely Thick Lens for -22 Myopia

The process of how eyeglass lenses are shaped as their prescription increases is something many people are curious about, but rarely witness. Before being fitted into the frames, the lenses are shaped according to the frame's mold in the cutting machine at optical shops. So, how is a lens with a prescription of 22 cut in this machine?

An optician answered this question by sharing a video on TikTok. The optician recorded the cutting process of the lenses prepared for 22 myopia and 1.5 astigmatism, showing every detail from the moment of measurement to the shaping process step by step.

The lenses used in glasses for myopia, also known as nearsightedness, are concave or negative lenses. The center of these lenses is thin, and as the prescription strength increases, the edges become thicker. Therefore, in glasses with a high prescription, the thickness of the lens is noticeably prominent at the sides of the frames. Myopia is defined as 'high myopia' when it reaches 6 diopters or above; the prescription strength of 22, as shown in the video, far exceeds this threshold.

To reduce the thickness, materials with a high refractive index, which bend light more (such as 1.67 and 1.74), are generally preferred in glasses with high prescriptions. These lenses can be much thinner and lighter compared to standard plastic lenses. Choosing a smaller frame is another method to decrease the edge thickness. It's important to clarify that 'high myopia' and 'pathological myopia', which involves structural damage at the back of the eye, are not the same thing. However, high myopia carries a risk for retinal problems, hence regular eye examinations are of utmost importance.