Our 3.1x TTLs (Through-the-Lens) provide higher magnification for those needing more power. Crystal clear lenses and custom fitted optics mean you can wear your loupes all day with greater comfort and less fatigue. Choose your TTLs on our Adidas Adivista frame or our classically-designed Ultralight titanium. Both options provide great protection and style. Prescription corrective lenses are available in both frame models.