The NAVMED 6150/2, Special Duty Medical Abstract, is a record of physical qualifications, special training, and periodic examinations of members designated to perform special duty, such as aviation, submarine, and diving. When members complete special duty physical examinations and special training, they should have entries made on their NAVMED 6150/2. NAVMED 6150/2 entries require the approval of a medical officer or designated specialty medical service corps officer (i.e., aerospace physiologist for aerospace physiology training).

If a special-duty-qualified service member is found to be physically or mentally unfit, the service member's special duty status will be suspended either temporarily or permanently. The reason(s) for the member's suspension and period of suspension are recorded on the NAVMED 6150/2. Special pay disbursements are often based on a member's physical and mental qualifications or continued requalification for performance in a special duty.

PHYSICAL EXAM TESTING PROCEDURES AND EQUIPMENT

LEARNING OBJECTIVE: Recall visual acuity, color vision, audiometric, and EKG test equipment and procedures.

Some of the basic procedures used to gather information for a physical examination are taught in Hospital Corpsman "A" School (e.g., vital signs, venipuncture, and height and weight measurements). However, other tests require advanced technical expertise, such as serological testing, and pressure and oxygen-tolerance testing. Some testing procedures may be learned by on-the-job training (OJT) or by short courses of instruction. These testing procedures and the equipment used will be discussed in this section.

VISUAL ACUITY
Visual acuity testing determines the ability of the eye to discriminate fine detail. It is the most important test of eye function. Throughout the Navy, there are two accepted methods for testing visual acuity: the Snellen chart and Jaeger cards, and the Armed Forces Vision Tester. The Snellen chart and Jaeger cards are used together to test visual acuity. The Snellen charts test distant visual acuity; the Jaeger cards are used to evaluate near visual acuity. The Armed Forces Vision Tester checks both distant and near visual acuity, and assists in evaluating other optical conditions.

The first step in testing for visual acuity is to find out if the patient wears corrective eyewear. On the day of their visual acuity testing, patients should bring in their glasses. Contact lenses are not recommended for use during visual acuity testing. Contact lenses cause an increase in time needed for testing purposes, and they tend to be an inconvenience for both the patient and healthcare provider. Acuity testing is performed with and without the glasses on, and the results are documented in blocks 59 and 61 on the SF 88. Visual acuity requirements are discussed in the MANMED.

Snellen Charts
Probably the most familiar of the visual testing equipment, Snellen charts, are the preferred method for testing distant visual acuity. Snellen charts can test both monocular and binocular visual acuity. Operational guidelines for Snellen charts are provided by the chart's manufacturer. Your local military optometrist or eye clinic can also provide you operational guidelines for Snellen charts. Specific details and current conditions for testing with Snellen charts are as follows:

If the examinee wears corrective lenses, have them remove the lenses before the examination.

Test the examinee first without corrective lenses, and then with the corrective lenses in place.

Hang the chart on the wall so the 20/20 line is 64 inches from the floor. Direct the examinees to stand 20 feet from the chart. Test each eye 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.