Subhadrika Sen
Use plain water to wash: Hold the specs under a gentle stream of water to wash off the dirt.
Safe dish-washing liquid: This may sound weird, but yes, light, dish-washing liquid is the safest cleanser for your specs.
Use micro-fibre cloth for cleaning: Always keep the micro-fibre cloth which comes in your specs case. After giving it a wash, wipe it with the same cloth.
Regular inspection: Observe your specs regularly for any loose ends, screw detachments, scratches etc.
Proper Storage: Always keep it wrapped in a micro-fibre cloth when not in use. Place it in its case and out of direct sunlight or heat souce.