According to the Global Eyewear Market report 2023, the sales volume of tortoise shell sunglasses has increased by 28.6% year-on-year, accounting for 19.3% in the high-end optical frame market. The oxygen permeability coefficient of its core material cellulose acetate has reached 28.5×10⁻¹¹(cm²/s)(mLO₂/mL·mmHg). The mirror leg bending strength test shows that it can withstand 90N pressure (ISO 12870 standard requirements ≥80N). Common products such as Ray-Ban RB3544N model, the frame weight is just 22 grams, the nose pad contact area is expanded to 38mm², and the wearing pressure distribution is optimized, facial indentation occurrence is reduced by 63% after 6 hours of continuous wearing.
For protection from UV, tortoise sheck sunglasses UV400 lenses screen out 99.97% of UVA/UVB (280-400nm wavelength), and the polarized one improves visual contrast to 92% in high light environments (compared to 78% for regular lenses). According to a 2024 market test, Gentle Monster’s Myma series of tortoise shell glasses with progressive colored lenses reduce hazard recognition reaction time by 0.3 seconds in driving environments (NHTSA test criteria). Yet the material characteristics make it have bad high temperature resistance, laboratory tests show that cellulose acetate glasses in 60℃ environment for 2 hours continuous exposure will result in 0.8mm distortion, hence the summer car warehouse tank store risk factor increased 2.4 times.
Price comparison shows the median price of regular brands of tortoise shell sunglasses is 180 (for example, WarbyParker’s Percey model), and luxury brands such as DiorSoReal series is as much as 450, a premium of 120% to 250% over general TR90 frames. During the production process, each pair of tortoisesbill frame has to go through 18 hand polishing processes (45 minutes/pair), and the material utilization rate is only 62% (normal injection molding process can reach 85%). Consumer reviews suggest that 73% of buyers believe its unique lines have status symbol appeal, although 27% of owners report that the mirror leg hinge is prone to layer separation (15.6% after 12 months of ownership).
In line with the corresponding scene data, the business setting choice rate of tortoise shell glasses was as high as 41% (compared with 29% of the metal frame), and its warm color pattern increased the facial visual temperature by 2.3 ° C (color psychological analysis). Within the optical parameters, the model with a mirror width of 54mm is suitable for people with an eye distance of 62-68mm, and the lens base bend design of 8.25 enables the peripheral distortion rate to be maintained at 4.7% (industry standard ≤6%). A 2023 study by the European Society of Ophthalmology demonstrated that its amber lens can improve scene recognition by 19% in cloudy weather, especially suitable for multiple environments with 10,000-25,000lux light intensity.
Regarding sustainable development, the biobased content of cellulose acetate has been increased to 38% (only 15% in 2022), and the carbon footprint is 42% lower than petroleum-based products. The Eco-Acetate line, created by Italian producer Mazzucchelli, contains 62% plant-based content and a frame degradation time of 12 years, as opposed to 500 years for conventional materials (ASTM D5511 test). The innovation in the production process added 28% to the cost, leading to an increase of 40-60 in the final retail price. Wearer experience testing shows that ergonomically reshaped hawksshell frames reduce daily adjustment frequency from 4.7 to 1.2, and peak pressure behind the ear from 32kPa to 19kPa (pressure sensing data).