M Madhu 🎓 Tutor II ⭐ 12.07K Points 📊 World History Q. When were concave spectacles invented? (A) 1286 (B) 1320 (C) 1360 (D) 1000 👁️ Show Answer 🔗 Share ⚡Menu ✅ Correct Answer: (A) 1286 You must be Logged in to update hint/solution 💬 Discussion 💬 Comment