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A prescription of −1.00 +0.25 × 180 describes a lens that has a horizontal power of −1.00 D and a vertical power of −0.75 D. Only ophthalmologists write prescriptions in + cylinder. An optometrist would write a prescription in - (minus) cylinder. All spectacle and contact lenses would be made in minus cylinder.
GI glasses are eyeglasses issued by the American military to its service members. Dysphemisms for them include the most common " birth control glasses " ( BCGs ) and other variants. At one time, they were officially designated as regulation prescription glasses ( RPGs ).
The U.S. military standard (MIL-PRF-31013), requires (at a minimum) that ballistic eyewear can always withstand a 0.15 caliber, 5.8 grain, T37 shaped projectile at a velocity of 640 to 660 feet per second (approximately 3.8 mm 0.376 g at a velocity of 195 – 201 m/s). Goggles are required to stop a 17-grain fragment simulating projectile ...
Ballistic sunglasses or prescription eyeglasses must meet the same requirements. In brief, the U.S. military standard requires that ballistic eyewear must be able to withstand up to a 3.8 mm (.15 caliber) projectile at 195 m/s (640 ft/s)) for spectacles and 5.6 mm (.22 caliber) projectile at 168–171 m/s (550–560 ft/s) for goggles.
[16] [18] Several studies have shown that blue light from computers does not lead to eye diseases, including macular degeneration. [16] [19] [20] The total amount of light entering the eyes can be adjusted without glasses using the screen brightness settings. Similarly, the blue light can often specifically be adjusted using the "night mode" of ...
These glasses are independently tested and are shown to filter 100% of harmful UV and infrared light, and 99.9% of intense visible light. This 10 pack is great for splitting among friends or a ...
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