My eye sight for one rye is -0.75 and other is +0.50 what can i do?

Depends: At your age, if no symptoms do nothing. You have what we call anisometropia, different refractions in eyes. Your right eye is near-sighted while left is far-sighted. Brain has one accommodation center. When your left eye focuses for distance, it makes your right eye -1.25 nearsighted. And when reading most probably you read with your right eye more often. If you have symptoms get glasses.

Nothing: At your age this should not be a problem unless you have a high demand for excellent depth perception, (varsity sports, fly fishing, etc) . Glasses can help if there is only occasional blurred vision, or consider contact lenses for daily correction.