Bring up UI and call function upon gaze (URGENT)

I am creating an architectural VR walkthrough of a house for android and i want to add interaction, like for example the user looks at a button which brings up a small menu to choose materials/colour. I am struggling and i have no idea how to do this, i need it done by the 15th of August. What i want to create is in the image attached.

 

You can use services like Unity Connect to hire contractors to do work for you.

I struggle to understand the thought process behind posting "Urgent - please do my work for me!" on a developer forum where people are helping one another with technical problems (doing work instead of asking others to do work for them, generally). Did you expect someone to volunteer to do your work for you? I guess crazier things have happened and the cost of asking was low.

 

Looking at the post now it's obvious that it seems that I was asking for someone to do the work for me by my choice of wording, but I was simply looking for advice or someone explaining the approach towards doing the work.