Because blue light waves are one of the shortest, strongest energy wavelengths in visible light spectrum, they can penetrate lens and directly reach retina. Our eyes do not have sufficient natural filters to protect against blue lights, especially young children. Prolonged exposure to blue light from digital screens or fluorescent / LED lights may cause eye strain, dry eyes, headache, difficulty sleeping, and even damage our retina photochemically and increase the risk of macular degeneration over time. 

Blue light wave is one of the shortest, highest-energy wavelength that's between approximately 380nm and 500nm in visible light spectrum. Blue light is actually everywhere including the sun, digital screens (TVs, computers, laptops, smart phones and tablets), electronic devices, and fluorescent and LED lighting. 

Natural blue light comes from the sun. Our body uses blue light from the sun to regulate our natural circadian rhythm (sleep and wake cycles), boost alertness, heighten reaction times, elevate moods, and increase the feeling of well being.

Artificial sources of blue light include digital screens such as TVs, computers, smart phones, and fluorescent and LED lights. 

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TR90: Super lightweight, durable and flexible TR90 material frame offers excellent wearing comfort and resilience to damage, far superior to cheap PC materials. Zero chemical residues in compliance with EU requirements for food grade materials. 

Ultra-thin Stretch Steel:  ultra light weight and flexible. With screw free and solder free design, the frame weights less than 17g (0.6oz) and can quickly restore the shape from external forces or drop. One piece design with welded fixing hinge eliminates screw loosening and other potential mechanical failures.

Carbon Fiber: aviation grade carbon fiber temple combined with ultra thin steel frame offers super light weight experience (only 19 grams in weight with lenses on). Carbon fiber has 10 times the strength of steel, strong and durable, known as the "Black Gold" in materials. 

Amber Tint Lenses: crystal clear and lightweight thermoplastic polycarbonate lenses, injection-molded, offer superior color perception, shatterproof and durability.

Tan Tint Lenses: Ultra-high elastic tan nylon lenses infused with ultra-anti-UV transparent crystal material would reduce scattering of visible lights. Excellent resistance to stress, cracking and chemicals makes it the first choice of material for high-end lenses.

Both types of lenses block 100 percent of harmful UV light, strengthen contrast and visual performance, and alleviate eye fatigue by filtering specific short-wavelength blue lights i.e. high-energy visible (HEV) lights, emitted from artificial light sources such as computers, tablets, smart phones, LED lights, TV, and other electronic devices.

All our lenses have passed FDA Drop Ball Test to ensure impact resistance and safety.

Our lens are made with advanced 5 in 1 coating technology to effectively block UV400 and electromagnetic radiation, filter out high energy blue light and other harmful light, imitate natural condenser, reduce glare and improve contrast, and restore true colors.  Anti-Reflective (AR) coating helps virtually eliminate glare and halos and allow for more beneficial light passing through, reducing digital eye strains and optimizing visual acuity (sharper vision) with fewer distractions. Functional coating layers offer fog, oils or stain-repellent, easy-to-clean, and abrasion and scratch-resistant benefits.

30-day Money Back Guarantee!

If you are not 100% satisfied with your glasses you can send them back within 30 days of purchase. We will refund returned order for the cost of the item not the shipping within 10 days of the ship date.  The purchase must have been made through our website, be in new condition and accompanied by a return authorization number (RMA).  A return authorization number  (RMA) can be obtained by contacting us or emailing to support@crystalhillglasses.com (Make sure to include your order number). We are not responsible for return shipping costs.

USPS First Class Package                        3~5 business days      

USPS Priority Mail                                     2~4 business days      

USPS Priority Mail Express                       1~2 business days     

USPS International shipping rate calculated at check out:

• First Class Package International

• Priority Mail Express International

• Priority Mail International

All orders are shipped from USA.  The buyer is solely responsible for import duties, taxes, and charges possibly required for international shipment. 

Please check with your country's customs to determine what these additional costs will be prior to ordering. 

Please contact us at support@crystalhillglasses.com for any special shipping request that may help make your custom clearance faster or easier. We'd be more than happy to assist you. 

1 year warranty that covers against defects after purchase.