Strange problem with new pair of glasses.

I got a new pair online, since the price was so low (thought I'd see
what I'd get for the money). The glasses seemed fine, but I notice
that my vision is only good if I keep look in the center. If I look
up, down, or to the sides, without moving my head, there is noticeable
blurriness. If I move my head and keep looking forward, there is no
problem. What is the problem likely to be here? It is a nearsighted
prescription, -3.50, with no astigmatism. Nothing was added, such as
a tint.

TIA.

On Jul 23, 6:39 pm, "Mike Tyner" <mty...@mindspring.com> wrote:
> <monty1...@lycos.com> wrote
>
> >I got a new pair online, since the price was so low (thought I'd see
> > what I'd get for the money). The glasses seemed fine, but I notice
> > that my vision is only good if I keep look in the center. If I look
> > up, down, or to the sides, without moving my head, there is noticeable
> > blurriness. If I move my head and keep looking forward, there is no
> > problem. What is the problem likely to be here? It is a nearsighted
> > prescription, -3.50, with no astigmatism. Nothing was added, such as
> > a tint.
>
> -3.00 lenses are only -3.00 when you look exactly perpendicular through the
> lens. That's why they're usually made with curved fronts, to "wrap around"
> and keep your line-of-sight as perpendicular as possible.
>
> Consequently, when you change frames, a different curve or a different
> distance-from-the-eye can create differences in the vision because you're
> looking at more or less oblique angles to the lens.
>
> If your frame can be adjusted closer to your eyes, or bent at the bridge to
> "wrap" better, the effect will diminish.
>
> Consider paying an experienced optician to help you solve the problem.
>
> -MT, OD

and remember to bring your old pair to the optician to compare with
the new set.