Can You Put High Prescription Lenses in Rimless Frames? High Minus Danger & Tensile Strength

In rimless glasses, there is no metal or plastic frame holding the lens. The temple arms and nose bridge are fastened directly to the lens via drilled mounting holes or compression bushings. When you put on or take off your glasses, immense mechanical shear torque is exerted directly on those tiny drilled holes:

$$\mathbf{\text{Tensile Stress Failure:}} \quad \text{Standard 1.50 or 1.74 Resin} \xrightarrow{\text{High Shear Torque}} \mathbf{\text{Radial Spider Cracks Around Drill Holes!}}$$

Standard 1.50 CR-39 plastic and standard 1.74 high index have low tensile shear strength ($<25\ \text{kgf}$). Using them in rimless frames leads to cracked lenses within weeks.

Optical laboratories universally recommend only two resin chemistries for drill-mount rimless glazing:

• 1.60 High-Index MR-8 Resin: The absolute global champion for rimless spectacles. It possesses a high tensile pull strength of $>80\ \text{kgf}$, will not shatter or crack under screw pressure, and delivers high Abbe value optical clarity ($V_d = 41$).
• 1.67 High-Index MR-7 Resin: Excellent tensile strength for higher powers ($-6.00\text{ to } -8.50\ \text{D}$), providing a thinner edge profile while remaining safe for drilling and grooving.

In a minus lens, the outer edge is thick. In a full-rim frame, the frame hides that edge. In a rimless frame, the entire $5\text{ to } 7\ \text{mm}$ edge is exposed to the world. If left unpolished, it looks like a thick white frosty wall. To make rimless high minus glasses look sleek, request a Hand-Beveled Satin Polish with Rolled Edges, which transforms the thick edge into a clear, gem-like crystal rim.