Hi 1) hydrate ur self with 4-5 litres of water 2) have good sleep, early to bed 3) eye exercises (10-100) times per day 4 ) for eye exercises search in google for Pencil push up test, ORTHOPTIC exercises 5) don't all any type of air or ac air to blow directly on to ur  face (eye) 6) give breaks inbetween your screen time works (give every 20 mins a small break, blink frequently, view near object then immediately view a distant object (20 feet ahead)) 7) don't rubb your eyes, give cold compressions 8)don't see any gadgets in a dark room , meaning in light switched off room 9)put ur gadgets is reading mode (with minimal brightness)

It is better to have Fresh Refraction, and take new glasses. Pl consult ophthalmologist for further evaluation and treatment.

Scratches have to be quite severe to cause eye strain by diffracting the light. Most likely, it can be either due to weak eye muscles causing convergence insufficiency or change in spectacle power

Eye strain can happen if you have a glass number and not using it.  Please consult local ophthalmologist for glass number check.

Yes scratch glasses can lead to strain But there are other reasons too Like muscle fatigue - convergence weekness