With the limited background that you have offered in this question, I will do my best to offer some guidance.
First, the spectacle lens prescriptions are not made exactly in the same power as the contact lenses. Manufacturers make lenses in certain powers and don't make them custom.
To derive a contact lens prescription from just the spectacle prescription in your power range will most likely create ill will between you and who ever attempts to do this because it will likely take 2-10 iterations before you'll be happy.
People who work with people who are unhappy with them for their work would like to get paid for being unhappy with them
If you are desperate to replace your contact lens prescriptions, you can always ask any retailer to sell you lenses on your old prescription which might be in violation of state law, but I have seen retailers do this.
In my opinion, you course of action is not wise.
You are asking me about a sign or symptom of a potential medical problem and I recommend that you see an eye care professional for your particular concerns. What I write here is not medical, legal or financial advice. This is not a solicitation.