Wearing Glasses For Myopia. Vision Correction Done. Still Having Headache, Reddish Eyes And Change In Vision

i had myopia in my both eyes of -2 power, now recent days I found headache , red eyes, when I show this to doctors they told my minus power is reduced and they given me -1.50 for Right eye and -1.75 for left eye, but they told me that initially wearing low power glasses can cause some discomfort, now I m wearing those low glasses and i can read all but left eye has some discomfort like mild pain and filmy type of vision , but have no problem with these glasses under tubelight