Given what we know about visual acuity measurements we can confirm that a score of 20/15 will indicate that<u> the patient has </u><u>better </u><u>than </u><u>normal vision</u><u>.</u>
Visual acuity is most often measured using a chart known as a Snellen chart. The goal of this is to place the patient at a distance of 20 feet and see how many lines in the chart he or she is able to accuratelyidentify. Though this method is becoming less common due to advances in technology, the dual number measurement system drives from these tests.
The numbers in the score indicate the size of the letters and the distance at which the patient can see them. Though 20/20 is considered the <em><u>optimal normal vision score</u></em>, a score of 20/15 will actually indicate evenbetter vision. This score indicates that at 20 feet, this individual can see <u>smaller letters</u> than the normal person.
Subtract your heart's resting rate from your maximum rate. For example, if you are 40 years old, subtract that number from 220; your maximum rate is 180. Next, subtract your resting rate or 80 in this example. Your heart-rate reserve is 100 beats per minute.