subvisible , także: subvisual

She turns us into microscopes: we see not only her characters' thoughts, purposes and actions but the gallivanting, subvisible antibodies that disarrange them.

This value is lower when considering clouds with an optical depth larger than 2 (0.56) and higher when counting subvisible cirrus clouds.

Garden of Microbial Delights: A Practical Guide to the Subvisible World (1988)