Horizontal prism - in far for Percival &#x7C; Eye &#x7C; Refraction
horizontal prism - in far for percival &#x7c; eye &#x7c; refraction
Horizontal prism - in far for Percival &#x7C; Eye &#x7C; Refraction
horizontal prism - in far for percival &#x7c; eye &#x7c; refraction