Surely you need. As long as you are nearsighted, you need a pair of prescription glasses to aid you. If you have mild myopia, you can choose to wear glasses with mild prescription. If you don' t wear glasses, I guess it will be very inconvenient for you. You especially need them when you are working or studying. You know, when driving, it will be dangerous if you can' t see things clearly. This is just an example, and I wish you could know the severe results if you don' t wear your glasses in time.
It's up to you. I have mild eye prescription. Both of my eyes need -3.50 lenses to see clear. And i have several pairs of prescription lenses. But i don't like to wear my eyeglasses all the time. I just worn it when i needed. If you think you can be normal life daily without wearing eyeglasses, you needn't wear eyeglasses. But if the poor vision prevent you work, learn or doing something, you are suggested to buy prescription eyeglasses.