Sony Bravia - 32 inch or 40 inch?

[mainman]

I plan on buying a new Sony Bravia tv.

I will either buy a 32" or a 40" tv (if I will buy 40" it will be full HD).

My viewing distance is about 3 meters (that's 118 inch, if my calculation is correct).

So what screen size should I pick for that distance?

Thanks

Edit:
I mean, I know 40" will look better than 32".
But is it wise to buy a 40" for such a distance, concerning health (headaches, eyes, etc)?