Why blue light blocking glasses? 1.Relieve symptoms of eye fatigue Blue light exposure during prolonged computer time would lead to eye fatigue. Wearing blue light blocking glasses to reduce the symptoms of eyestrain, like dry eyes, sticky eyes, and the feeling of grittiness or "sand" in the eye. Great for office and gaming occasion. 2.Reduce symptoms of headache Do you suffer headaches from long time screen time?Blue light blocking glasses blocks detrimental blue light while letting in all other beneficial light. 3.Sleep better This blue light messes with our internal clock making us think it's mid day when really it can be closer to night and stops our body from naturally producing the melanin that helps us fall asleep late at night. Wearing blue light filter glasses will improve your sleep after a long time exposer to computer or cellphone. Specification: Width of the forehead frame :140mm/ 5.51" (approx.) Lens Height:30mm/ 1.18" (approx.) Lens Width : 53mm/ 2.09" (approx.) Leg Length :140mm/5.51" (approx.) Material:PC Frame/AC Lens [Kindly Notice]: 1.Due to the difference between different monitors, the picture may not reflect the actual color of the item. 2.Size for manual measurement, there may be a 0 to 1 cm error, belongs to the normal phenomenon. 3. Diopter available: +1.0/+1.5/+2.0/+2.5/+3.0/+3.5/+4.0,Please specify the frame color and lens strength when pay for this. Package includes: 4xReading Glasses； 4xhard protection case; 1xsoft clean cloth; 1xglasses cord; 1xblue light blocking test card and torch If you have any problems with our items or services, please feel free to contact us . We will do our best to solve any problems and provide you with the best customer services.