Applying an image with an alpha mask to a plane I want to place a png file floating over my 3D model's face to create eyes. I've placed the image on a plane that I've UV unwrapped.

The problem I have is that when I render the image, you can see straight through his head.

How can I achieve the desired result?

I'm new to blender so go easy :)
This looks like bad alpha sorting in the viewport. It should be fine in the rendered view.

Essentially, Blender's old GLSL viewport has pretty mixed results with drawing transparency. this should be fixed in the new 2.8 Eevee based viewport.