according to his classical formula V = d/D, where d is the distance at which the letters are read, and D is the distance at which the letters should be read. Therefore, record the smallest line read on the chart from the 20-foot distance as the vision, i.e., 20/20, 20/200.
Use Jaeger cards to test near vision but only when the Armed Forces Vision Tester is not available. There are six paragraphs on each card. Each paragraph is printed in a different size type and labeled as J-1, J-2, . . . , or J-6.
When testing the examinee, hold the card at a distance of 13 inches (30 cm) from the examinee and tell the examinee to read the paragraphs. Record the visual acuity as the smallest type comfortably read and the distance, i.e., J-2 at 30 cm.
The Armed Forces Vision Tester (AFVT) is a semiportable machine that has the capability to test near and distant visual acuity, horizontal and vertical phorias, and steropsis (depth perception). It consists of two rotating drums that hold illuminated slides for the various tests. The handles on the side of the machine rotate the drums to change the slide. A scoring key and instruction manual are provided with the machine. The Manual of the Medical Department also provides detailed instruction on the use of the AFVT.
The Manual of the Medical Department requires that all applicants for entrance into the naval service receive a color vision test. The Navy has two methods of testing color discrimination: the Farnsworth Lantern Test (FALANT), and the pseudoisochromatic plates (PIP). The FALANT is the preferred, and in many cases the only acceptable, method for testing color vision.
The Farnsworth Lantern Test was devised as a means to pass personnel with normal color vision and those with a mild degree of color blindness. The Farnsworth Lantern is a machine with a light source directed at the examinee. What the examinee sees is two lights in a vertical plane, either red, green, or white, shown in varying combinations, i.e., red and green, red and red, etc. Have the examinee identify the color combinations from top to bottom at a distance of 8 feet; the examiner rotates the drum to provide the different combinations. There are a total of nine different combination that the examinee must identify.
On the first run of nine lights, if the examinee correctly identifies all nine, the FALANT is passed. If the examinee incorrectly identifies any of the lights, either top, bottom, or both, do two additional runs of nine lights without interruption. The score is the average number of incorrectly identified lights of the second two runs. If the average score is 1 or less, the FALANT is passed. If the score is 2 or more, the FALANT is failed. If the score is 1,5, repeat the test after a 5-minute break. Do not retest scores of 2 or more as this will invalidate the test procedure. NOTE: If the examinee wears corrective lenses for distant vision, he or she should wear them during this test.
Use pseudoisochromatic plates to determine color vision only if the FALANT is not available. Personnel so tested must be retested with the FALANT at the first activity they report to that has a Farnsworth Lantern. Two sets of plates are available: the 18-plate test and the 15-plate test, each of which has one demonstration plate not used for scoring.
When administering the PIP examination, hold the plates 30 inches from the examinee. Allow two seconds for each plate identification, and do not allow the examinee to touch the plates. TO pass the 18-plate test, the examinee must identify a minimum of 14 of the 17 test plates; for the 15-plate test, a minimum of 10 of the 14 test plates. Record the score in block 64 of the SF 88 as Passed PIP or Failed PIP, with the number of correct responses, i.e., Passed PIP 17 of 17 or Failed PIP 10 of 17.
Hearing of all applicants for enlistment, appointment, or commissioning is tested by audiometers calibrated to either American Standards Association (ASA) or International Standards Organization (IS0) standards. All audiometric tracings or audiometric readings recorded on reports of medical examination or other medical records will be clearly identified with Results ASA-1951 or Results ISO-1964. Audiometric