Did the eye doctor scam me?

Went to eye doc today who told me I have 20/20 vision in 1 eye and 20/20+ In the other (I went to get colored contacts) and she said she would write me a prescription but when I said why would I need one she got super defensive. This is what she wrote:
Od: -0.25x180
Os: -0.50x 180

My vision feels fine and I really feel I was scammed. At first, she did an eye pressure exam and lense exam and said I need a 'strong prescription' then did an eye exam and said I have 20/20 (the exam lasted less than 10 min and she was VERY pushy for payment and was late to the appointment) and now I have this perscription. I am concerned for my health and after I kept asking her she said I don't need a perscription if "I don't want". Please help I'm only 19 and freaking out. Thanks.

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