pinhole test

pinhole test,

1 a test performed on a person who has diminished visual acuity to distinguish a refractive error from organic disease. A refractive error may be corrected with glasses, whereas organic disease may signal the development of preventable blindness. Several pinholes, 0.5 to 2 mm in diameter, are punched in a card. The patient selects one and looks through it with one eye at a time, without wearing corrective lenses. If visual acuity is improved, the defect is refractive; if not, it is organic. The pinhole effect results from blocking peripheral light waves, which are most distorted by refractive error.
2 a test to determine the size of the focal spot of an x-ray tube.
3 a test to trace the path of x-ray tube movement.
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For example, each HUGE Brand condom must pass an electronic pinhole test, as well as an electrolytic water leakage tests to ensure that each condom will bring the utmost in reliability and quality.