How do I make the eyes in my Lens reflective?

To make the eyes in your Lens reflective:

Create an Eye Color object by selecting Add New -> Eye Color in the Objects panel.
Change the mode to Texture in the Inspector panel with the new Eye Color Object selected.
Assign any texture like echopark_diff or Device Camera Texture to the Iris Texture.
Adjust the Alpha and play with the Blend Mode to make it realistic.