tempered glass light features

Is there a style of tempered glass that would be difficult to see through and yet allow the same amount of light as clear tempered glass?

I need as much light as possible to filter through the glass, but also I wish to make it difficult for anyone to see through the glass. I have been told by some glass vendors that tempered frosted glass will give the same light as clear tempered glass ,but other vendors said you will get less light. Who is correct?

A response will be greatly appreciated.