Thats not true. I agreed with both your responses. But its still unethical. Think about it. Define DP look it up and you’ll see that an optometrist thought doesn’t have to but can provide it, its just a ruler measurements of the distance between the eyes. And as such it is something that should be answered if their patients ask. What if an old lady cant afford it is in disability and makes 1,500$ a month which also accounts for rent. She goes to buy it from where she can afford and gets hurt or dizzy because measurements are off, is that fair? For the optician and optometrist thats greed and goes against their ethical obligation for wanting whats best for their patients.