The Fujifilm Polaris 10x50 FMTR Binocular offers high optical performance and reliability which has made it a staunch favorite among professional users. This binocular is ideal for astronomy, marine, and bird watching. This binocular offers superb optical performance and value. This binocular deploys Fujinon's unique EBC coating, allowing 95 percent light transmission. With a field flattener lens, it offers edge-to-edge sharpness, free of any discernible astigmatism or distortion. Unique Light TransmissionThe Fujinon’s unique EBC coating allows 95 percent of light to pass through the binocular which is great for low-light performance. DurabilityIt features a robust body with an airtight, waterproof structure, enabling use in harsh conditions from -20-degree-C to +50-degree-C. Eye ReliefThis binocular features a long eye-relief design with a maximum length of 19.8mm. Eye relief refers to the distance between one’s eyes and the eyepiece that still allows one to view the entire field of vision. Long Eye Relief binocular allows one to see right up to the edge of the field of vision even while wearing glasses, with this distance at over 15 mm.