subvisual

adjective
sub·​vi·​su·​al | \ ˌsəb-ˈvi-zhə-wəl How to pronounce subvisual (audio) , -zhəl; -ˈvizh-wəl\
variants: or sub-visual

Definition of subvisual

: not visible without the aid of special instruments : subvisible … once you have seen the subvisual world through the microscope, you stop inventing demons and magic as the agents of change.— Dava Sobel Auroras have a wide range of brightness, usually rated from 0 to 4 on a logarithmic scale … in which each number is 10 times brighter than the previous one. Zero means subvisual, detected only with instruments.— Robert H Eather

First Known Use of subvisual

1873, in the meaning defined above

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