Minus glasses or myopia....things you can do wear your glasses regularly Decrease your near screen time/ near activity. Increase outdoor time,vitaminD is good for eyes. Have green leafy vegetable n yellow fruits...spinach,papaya ,mangoes Get your eye checkup....if your no.is stable that’s good,if it is increasing,eye doctor may start some drops n treatment as per the case

According to history given I guess you are having a refractive error we commonly call nearsightedness or shortsightedness, medical terminology is Myopia. Mostly in myopes the spectacle power goes on increasing because of increase in the axial length of the eyeball which gets fixed and the number becomes stable after a certain age between 18 to 21 years. At this age of 16 year it's better to do a 6 monthly eye check up and annual dilated retina check up to rule out any myopic degenerations of retina. In general term if I can explain its like due to elongation of eye ball there occurs some stretching of curtain like structure we call Retina, this stretching can go into thinning or even a small hole through which the fluid inside the eye can seep in and go behind retina and push it forward we call Retinal detachment. But detected early we can do simple lasers on retina as prophylactic treatment. There are other myopic degenerations too which should be ruled out. To reduce the number we have lot many options under refractive surgery like LASIK, Clear lens exchange, etc depending on the preoperative work up but all this can be done in your case after the age of say 21 years.

You might be suffering from pathological myopia.... We need to do indirect ophthalmoscooy to rule out peripheral retinal degenerations... And we need to see your axial length In this case frequent change of power will occur

Possibly you are talking about myopia or minus power spectacles..since mostly it is related to growth of eyeball it doesn’t reduce.Infact it keeps on increasing till your till growth gets stabilised..there are some medication to stabilise growth but that may not be effective at 16 yrs of age ..but what is important is to have regular eye check with ur doctor to rule out any retinal problems