Frequently Asked Questions

Q: How quickly does the photochromic tint actually change?
The silver halide photochromic layer transitions from clear (Category 1, ~80% VLT) to dark (Category 3, ~15% VLT) in approximately 15-20 seconds under direct UV exposure. The fade-back to clear in low-light conditions takes 30-60 seconds. This response curve is optimized for the kind of variable-light riding you encounter on tree-lined roads, through tunnels, or during cloud-cover transitions—about twice as fast as standard photochromic eyewear you would find at a drugstore.

Q: Can I wear these with a prescription insert or over my regular glasses?
The frame geometry accommodates most low-profile prescription inserts behind the main lens. The internal width is 138mm with 18mm of depth clearance, which fits the majority of aftermarket RX adapters. They are not designed as over-glasses (OTG) fitment—the wrap-around curvature will conflict with most prescription frames. For best results, use a dedicated RX insert clip designed for ROCKBROS or similar sport-frame geometries.

Q: How durable is the frame in a real crash?
The TR90 thermoplastic frame is rated for impact resistance exceeding ANSI Z87.1 standards. In practical terms: it will flex and absorb energy rather than shatter. The hinge mechanism uses a stainless steel spring-loaded cam that allows the temple arms to flex outward beyond 90 degrees without snapping—this is the most common failure point on budget cycling glasses and the primary reason the ROCKBROS design costs more to manufacture. The lens itself is polycarbonate with a scratch-resistant hard coat.

Q: Do these work for running, hiking, or other non-cycling activities?
Absolutely. The wrap-around geometry, hydrophobic coating, and adaptive tint make them equally effective for trail running, alpine hiking, road running, and watersports. The only activity-specific limitation is ventilation: the frame includes micro-venting channels at the brow line optimized for the forward-leaning riding position (approximately 45 degrees). When standing upright, airflow is slightly reduced but still adequate for most non-cycling use.

Q: What is the maintenance routine for photochromic lenses?
Rinse under cool running water before wiping—never dry-wipe road grit across the lens surface. Use the included microfiber pouch for storage and cleaning. Avoid ammonia-based glass cleaners (Windex, etc.), which degrade the hydrophobic coating and can accelerate photochromic fatigue. The photochromic layer has an expected service life of approximately 2-3 years of regular use before the tint range begins to narrow. Store in a ventilated case—do not leave in a hot car dashboard, as sustained temperatures above 70°C permanently damage the photochromic molecules.