Contact prescriptions for different lens type?

are there different contact prescriptions for different brands of contact lens?

my optometrist only prescribed me for acuvue 2 lens (oasys), but now ... (6 months later) i need focus dailies because i think i have an eye infection.

so i went to a local costco and find out that i couldn't get focus dailies because it wasn't prescribed in my prescription...
i went to their optometrist to see if she could do something about that... but she said i needed to talk to the optometrist that wrote up my prescription.

can you please explain why..

thanks.

To put it simply: contact lenses come in different sizes and materials.... and they all fit differently! This means each contact lens fit needs to be monitored by an eye doctor to ensure proper fit to prevent discomfort and even possible damage by ill fitting lenses.
In the USA contact lenses are regulated by the FDA and it is required to have a valid prescription to buy contact lenses. The type of lens is a part of the contact lens prescription and the stores refusing to sell you the lenses are just abiding by the law (and it is also in your best interest)

So if you suspect you have an infection it would be best to not wear contact lenses at all and see an eye doctor.... if you want to switch types of contact lenses you will need to see your eye doctor anyways :)

yes
the opt. prescribes a specific lens to you your eye. and noone can dispense you a different one till you see the dr again.
I use the same ones you do and love the. Each brand can fit differently so thats why it is unique to you.

I tried to do the same thing and was turned away. They told me that contacts are often fitted. Different contacts and shapes for different eye issues. Sooooo, even if you are sure the Focus Daily's are the right lens for the infection, your doc needs to write a prescription for the change. Isn't that frustrating! I just called my doctor and he called in the perscription over the phone.

Different brands of contacts have different measurements, more specifically base curve measurements. These measurements affect how well the contact fits on your eye. Focus dailies have an 8.6 BC, while the Oasys have an 8.4. Personally, I have tried many different kinds of lenses with very different base curve measurements, and honestly never felt a difference between them. But everyone is different.

If you take your rx to a different office to get contacts filled, they have to honor the prescription as is. No one can alter another doctors prescription, so if it says Oasys, they can only give you Oasys. Tell you doctor you want to try Focus Dailies, and you should be fitted for them if you can wear them.