Since the cornea is avascular, which renders it optimally transparent, the nutrition of the corneal epithelium, stromal keratocytes, and corneal endothelium must occur via diffusion of glucose and other solutes from the aqueous humor, across the corneal endothelium.
6 an examination in the practical skills of a subject. a science practical. (C17: from earlier practic, from French pratique, via Late Latin from Greek praktikos, from prassein to experience, negotiate, perform) â¦ practicality, practicalness n. A distinction is usually made between practical and practicable. Practical refers to a person, idea, project, etc., as being more concerned with or relevant to practice than theory: he is a very practical person; the idea had no practical application. Practicable refers to a project or idea as being capable of being done or put into effect: the plan was expensive, yet practicable.
Necessity is the mother of invention in such related fields as electrical and electronic wiring. These two separate but equal fields use the same basic concept--connecting one source or signal to many devices. The technology is known as the breakout box. In both electrical design and electronic design there will often come a time when a multitude of units need to be attached to one line of voltage. In electrical work, for instance, there may be a need to install four power outlets but hook them to one line of voltage.