It's hard to say if your eyesight through each eye should be identical. Most people will have one eye slightly better than the other, and this is sometimes more noticeble when there is different types of correction for each eye,and some people have more difference than others (such as those with lazy eyes etc).
The main questions - Has this been noticed by you in the past? Where you noticing this issue when you had your eyes tested and did you discuss this with your optometrist? If you feel your new specs aren't right why not go back and discuss this with them?