Severely reduced visual acuity Severe reduction in visual acuity Severe reduction of the ability to see. On the 6m visual acuity scale, severe reduction is defined as less than 6/60 but at least 3/60. On the 20ft visual acuity scale, severe reduction is defined as less than 20/200 but at least 20/400. On the decimal visual acuity scale, severe reduction is defined as less than 0.1 but at least 0.05. HP:0007951 Severe visual impairment HP:0007842 Severe visual loss HP:0008023 Severely impaired vision HP:0007640 UMLS:C1301509 SNOMEDCT_US:397541004 Severe vision loss HP:0001141 Marked vision impairment Reduced visual acuity