snellen chart in Medicine Expand. Snellen chart SnelÂ·len chart (snÄl'Én) n. A chart for testing visual acuity, usually consisting of letters, numbers, or pictures printed in lines of decreasing size which a patient is asked to read or identify at a fixed distance.
Vanilla is a flavor derived from orchids of the genus Vanilla, primarily from the Mexican species, flat-leaved vanilla (V. planifolia). The word vanilla, derived from the diminutive of the Spanish word vaina (vaina itself meaning sheath or pod), translates simply as little pod.
Vanilla Cultivation & Processing. Vanilla is the most popular flavor in the world! It is also the second most expensive spice flavoring agent and the reason for itâs high cost is that it is the most time and labor-intensive crop when taken in consideration cultivation and processing.