individually, then both eyes together. Do not allow the examinee to squint or tilt his head.  With the graduation of the size of the letters advocated by Snellen, the visual acuity is expressed according to his classical formula V = d/D, where “d” is the distance at which the letters are read, is divided by “D” the distance at which the letters should be read. Then record the smallest line read on the chart from the 20-foot distance as the vision; e.g., 20/20, 20/200. Jaeger Cards When the Armed Forces Vision Tester is not available, Jaeger cards are used to test near vision. There are six paragraphs on each card. Each paragraph is printed in a different size type and labeled as J-1 (the smallest print size), J-2,..., up to J-6. When testing with these cards, you should hold the card at a distance of 14 to 16 inches from the examinee and tell the examinee to read the paragraphs. Record the visual acuity as the smallest type he can comfortably read and record the distance (e.g., J-2 at 14 inches). NOTE: The distance of the card from the examinee may be converted to centimeters, but ensure the results of the test are also recorded in centimeters. Consistency is the key. Armed Forces Vision Tester 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 stereopsis (depth perception). It consists of two rotating drums that hold illuminated slides. The handles on the side of the machine rotate the drums to change the slides. A scoring key and instruction manual are provided with the machine. COLOR VISION TESTING The Manual of the Medical Department requires that all applicants for 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 test, and in many cases it is the test prescribed by the MANMED as the only acceptable method for testing color vision. Farnsworth Lantern Test The purpose of the Farnsworth Lantern Test is to evaluate color perception. 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. These lights appear in two of three possible colors, either red, green, or white, shown in varying combinations. The examinee is asked to identify the color combinations from top to bottom at a distance of 8 feet; the examiner rotates the drum to provide the different combinations. The examinee must identify a total of nine different combinations. 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, two additional runs of nine lights are performed 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, the test should be repeated after a 5-minute break. Do not retest scores of 2 or more since this will invalidate the test procedure. NOTE: If examinees wear corrective lenses for distant vision, they should wear them during this test. Pseudoisochromatic Plates If the FALANT is not available, pseudoiso- chromatic plates (PIP) are used to determine color vision. Personnel so tested must be retested with the FALANT at the first activity they report to that has a Farnsworth Lantern. Two tests are available, the 18-plate test and the 15-plate test, each of which includes one demonstration plate not used for scoring. When administering the PIP examination, you should hold the plates 30 inches from the examinee. Allow 2 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. Include the number of correct responses (e.g., PASSED PIP 17 of 17 or FAILED PIP 10 of 17). AUDIOGRAM An audiogram is a record of hearing thresholds an individual has for various sound frequencies. By 11-11