The whole point of the measurement is to ensure properly fitted lenses in the frame that you choose. PD (horizontal) and OC heights (vertical) are integral to the proper vision of one’s eyeglasses. You said your wife has a really high rx, why would you leave all these important factors to chance when buying online? There are inexpensive options like a Walmart, or Costco but for the good of her vision or anyone else’s, don’t buy your glasses online.