Does Glass Thickness Affect Light Focus and Virtual Image?

[UrbanXrisis]

I was wondering if there is a difference between trying to focus a beam of light through a think piece of glass versus a thin layer of glass?

 

[Chi Meson]

Are you talking flat glass, with both sides perfectly parallel to each other? If so:

A double-plano piece of glass will have all rays emerging parallel to their incident rays. But within the glass, any rays not normal to the surface of the glass will be refracted while inside the glass. The overall effect is that an already focusing set of rays will have the effective focal length lengthened by a piece of flat glass inserted between the lens and the image position.

 

[UrbanXrisis]

but does changing the thinkness of the double-plano glass effect the virtual image at all?