Transparency in viewport?

Theres a chance that this is a very stupid question, so bear with me:

Why cant i see transparency of transparant Vray materials in the max viewport, like when using the scanline render?

So far ive had to use the “see-through” option under display properties, to get transparency in the viewport when using Vray glass. Is this the only way?

because Vray don’t use transparency, it use refraction…

Anyhow, it would be nice to have the refraction value take for tranparency, to help identifying glas or very transparent objects.

regards,

robert