I don't know quite what to make of this, it strikes me as being in the "can't possibly be true" category. For one thing, I don't think it's true that light emitted by antimatter would be refracted differently than light from ordinary matter, since the photon is its own antiparticle, there is no "antiphoton". But in the interest of maintaining an open mind, I present the following:

An article at the in5D website:
~~~~~~~~~~~~~~~~~~~~~
New Lens Detects Invisible Entities
by Gregg Prescott, M.S., Editor, In5D.com - January 27, 2016

A new type of lens was recently discovered that can detect invisible entities around military installations and industrial sites.

This new lens, discovered by Thunder Energies Corp., is concave and has the ability to detect antimatter, including invisible entities.

According to Thunder Energies CEO, Dr. Ruggero Santilli, “This is an exciting discovery. We do not know what these entities are; they’re completely invisible to our eyes, our binoculars, or traditional Galileo telescopes, but these objects are fully visible in cameras attached to our Santilli telescope.”

Dr. Santilli added, “Those entities appear to conduct unauthorized surveillance of rather sensitive civilian, industrial, and military installations.”
~~~~~ CONTINUE AT: ~~~~~

http://in5d.com/new-lens-detects-invisible-entities/

A description of the technology at the Thunder Energies Corporation website:
http://thunder-energies.com/index.php/ct-menu-item-18/11-articles/17-article-8

A PDF which is similar but not identical to the above page:
http://thunder-energies.com/tecuploads/docs/TEC-OPTICAL-DIV.pdf

A PDF of a research paper on the topic from an e-published physics journal I never heard of:
http://www.santilli-foundation.org/docs/antimatter-detect-2014.pdf