2. Overall, the Microsoft HoloLens received the highest level of recommendation for both validity and level of effectiveness.



 The Microsoft HoloLens has shown the most promising results across all parameters and produced improved performance measures in surgical trainees. 
Microsoft HoloLens
PUBMED, EMBASE, Google Scholar, Cochrane Library, British Library and Science Direct were searched following PRIMSA guidelines. 
PRIMSA
PUBMED, EMBASE, Google Scholar, Cochrane Library, British Library and Science Direct were searched following PRIMSA guidelines. 
Google Scholar
PUBMED, EMBASE, Google Scholar, Cochrane Library, British Library and Science Direct were searched following PRIMSA guidelines. 
Cochrane Library
PUBMED, EMBASE, Google Scholar, Cochrane Library, British Library and Science Direct were searched following PRIMSA guidelines. 
British Library
PUBMED, EMBASE, Google Scholar, Cochrane Library, British Library and Science Direct were searched following PRIMSA guidelines. 
Science Direct