I'm the libvips maintainer. Sorry, it's very difficult to use the pre-built libvips binaries with VS, for various reasons (see below). I think your options are to use mingw instead, to cross-compile from linux (this is what I do), or to rebuild libvips yourself from source using VS (perhaps a week's work for an experienced dev?). There are some notes on the vips website about this issue.
The libvips.dll on the website has been cross-compiled from linux using mingw. It's set up for a linux-style build system with pkg-config, so you will have a lot of compiler flags to figure out in VS, and it's built against msvcrt.dll, the Windows C runtime, rather than msvcrtXX.dll, the VS runtime, so you will have endless annoying compatibility problems unless you also build against the Windows runtime.
Unfortunately VS no longer supports building against the Windows runtime. They have an internal tool which does support this mode, but it's not publicly available. I read somewhere you can coax the DDK compiler into doing this, but it's also not supported.
CoApp is an interesting project (partly supported by Microsoft) that is attempting to make building software on Windows less painful, but it's still in beta. You could maybe ask if they have a libvips packaged up for VS, or are considering making one.