Myodisc

Myodisc refers to a type of spectacle lens designed to correct high myopia (nearsightedness), particularly in children. These lenses are characterized by a strong minus (concave) power in the central area for correcting vision, surrounded by a less powerful or even plano (zero power) carrier portion.

The purpose of the myodisc design is twofold. First, it provides the necessary optical correction for clear central vision. Second, the carrier portion of the lens reduces the overall thickness and weight of the lens, especially at the edges. This is particularly beneficial for individuals with very high prescriptions where traditional lenses would be excessively thick and heavy, improving cosmetic appearance and wearing comfort.

Myodisc lenses are typically made of plastic materials due to their relative lightness and shatter resistance. They can be fitted into standard spectacle frames, though the frame selection might be limited by the lens's thickness at the transition zone between the corrective and carrier portions. The lens appearance can be noticeable, with a distinct demarcation between the central correcting area and the surrounding carrier portion.

The popularity of myodisc lenses has decreased with the advent of high-index materials and aspheric lens designs, which can achieve similar optical correction with thinner and lighter profiles. These newer technologies often provide better cosmetic results and a wider range of frame choices. However, myodisc lenses may still be considered in certain specific cases depending on individual prescription requirements and preferences.