Can eye doctor convert eyeglasses RX into Contacts RX?

[Mauricio]

I got my glasses prescription less than a year ago, I've just decided to order some contacts,I am wondering if the eye doctor can convert eyeglasses RX to contacts RX, or if I need a new exam.

[Jamari]

The power of contacts can be calculated from that of glasses.Here is a formula :Fo=Fs/(1-dFs).The Fo means your power of your contacts and Fs means the power of glasses. dFs means the distance between rear vertex of glasses and your cornea.Usually the dFs should be measured by meter and it is 0.012m for easterners.For example,the RX of glasses is -4.00,the dFs is 0.012m,we can know that your RX for contacts should be -3.82,but this result is not a regular RX,so we choose the proximal and a lower number , it should be -3.75 . Hope these can help. But even if you can make out the RX,you still need an eye exam for contacts.

[Abram]

Of course not ,the RX of contacts is different from that of glasses as they are worn directly on your eyes.Also the doctor need to check if you are the right candidate for contacts,so it is necessary that getting an eye exam before wearing contacts.