Kai Bio-Based
Kai Bio-Based
Prescription
Prescription
✓ Progressive
✓ Blue Light Blocking
✓ Photochromic Lenses
✓ Reading
✓ Color Tint
✓ Driving Lenses
Services & Guarantees
Services & Guarantees
- FSA/HSA Eligible
- 45-Day Exchanges & Returns
- 365-Day Warranty
- 3-Day Shipping Available
- Free Shipping Over $90
The Ray-Ban Kai Bio-Based (RB3757) is a unisex full-rim narrow oval — almost diamond-shaped — sunglass in lightweight metal. The pictured Gunmetal colorway pairs a polished silver-grey wire rim with polarized teal-grey lenses and red-brown acetate temple tips. Built on Ray-Ban's bio-based metal program. Compatible with prescription lenses, single-vision through progressive.
- Frame shape: Narrow oval (diamond contour)
- Rim style: Full-rim
- Frame material: Metal (bio-based)
- Gender: Unisex
- Size: Medium
- Measurements (56 mm / 59 mm): 56 or 59 mm lens · 34.2 or 36.1 mm height · 15 mm bridge · 145 mm temple · 127 or 133 mm total width
- Colors: Gunmetal, Gold, Silver
- Configurations: Non-prescription or Prescription, in 56 mm or 59 mm
- Lens options: Single Vision, Bifocal, Progressive
- Coating options: Blue Light, Photochromic, Anti-Reflective, Anti-Scratch
Single Vision
Corrects vision for one distance, like reading or driving. Simple and effective for daily use.
Bifocal
Combines near and far vision in one lens with a visible line. Great for switching between tasks easily.
Progressive
Blends near, mid, and far vision smoothly with no lines. Ideal for all-day versatility.
Blue-Light Blocking
Reduces eye strain by filtering harmful blue light from screens and devices. Perfect for long hours of digital use, it helps improve sleep quality and comfort.
Photochromic
Adapts to light changes, darkening outdoors and lightening indoors for convenience. Protects against UV while ensuring all-day comfort.
Anti-Glare
Minimizes reflections and glare from bright lights or surfaces for sharper vision. Ideal for driving or outdoor activities, it enhances clarity and reduces fatigue.
Shipping Information
Free U.S. shipping on orders over $90
Shipping rates start from $9
U.S. Shipping
• 3 Business Days
• 6 to 9 Business Days
• 10 to 14 Business Days
Local Pick-Up (Free)
International Shipping
• Rates calculated at checkout, duties and taxes may apply
365-Day Warranty
Covers manufacturing defects for 365 days; does not cover damage from accidents, neglect, or improper care.
45-Day Easy Returns & Exchanges
Return, exchange, or refund within 45 days for any reason—hassle-free.
VISION GLOBAL
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EASY RETURNS AND EXCHANGES
Return or exchange your order within 45 days with no hassle.