Is there any kind of eye drop to dialate your pupils?

I like to use Oxycontin once or twice a month for recreational use, but my mom is very smart and aware, and she looks online to find out how someone is high and what they are high on just by body signs, so If she sees me with really small pupils, she'll automatically ume im high on pills. Ive already got eye drops to keep my eyes clear when I smoke pot, but is there any kind of drops to make pupils bigger (because on oxycontin, it reduces the size of pupils significantly). and before any of you bash me for being a low life addict, notice I say once or twice a month!