These GRS spectacle-friendly 10x eyepieces are drop-in replacements for the standard Meiji 10x eyepieces. They feature a special extended relief system for a full field of view even while wearing prescription eyeglasses. A rubber ring protects spectacle lenses from being scratched. These special eyepieces are made with the same high-quality Japanese optics that come in the standard Meiji eyepieces.