The -- The word translated as "the" is the Greek definite article. The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those") that the English "the." See this article for more. 

eye: -- (WP) The Greek word for "eye" is the more technical terms for "eye" but it also means "sight". It is a metaphor for "cheer."

is -- The Greek word translated as "is" is the active, present form of "to be."

the -- The word translated as "the" is the Greek definite article. The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those") that the English "the." See this article for more. 

lamp -- The word translated as "lamp" means a portable light, a lamp. Jesus uses "light" as a metaphor for knowledge and awareness, specifically that which allows use to perceive information.

of -- This word "of"  comes from the genitive case of the following word that required the addition of a preposition in English.  The most common is the "of" of possession, but it can also mean "belonging to," "part of", "which is", "than" (in comparisons), or  "for", "concerning" or "about" with transitive verbs. 

the -- The word translated as "the" is the Greek definite article. The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those") that the English "the." See this article for more. 

body -- The words translated as "body" means "body" but it also means "the substance of things" generally, as we use the term "a body of evidence." So generally, it refers to material existence. Christ uses another Greek word to refer more specifically to his physical body or "flesh".

If-- The Greek word meaning "if might" indicates more of an expectation of something happening than "if" alone. This is often how we use the word "when".

missing "really"-- (MW) The untranslated word "really" either emphasizes the truth of something ("certainly", "really") or it simply continues an existing narrative, "then," "therefore.

your -- The word translated as "your " is the genitive form of the singular, second-person pronoun, which is most commonly the possessive form. This pronoun follows the noun so "of yours."

missing "the"  -- (MW) The untranslated word is the Greek definite article, "the." The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those"). See this article for more. 

eyes -- (WN) The Greek word for "eye" is the more technical terms for "eye" but it also means "sight". It is a metaphor for "cheer."

are -- The Greek word translated as "are " here is in a form indicating something that "might be." In English, this form is assumed with the "if/when" that begins the phrase.

healthy, -- (WW) The Greek word translated as "single" means "single" which makes the KJV closer to the Greek than many more modern translated that render this word as "healthy/good". The adjective form means anything from "straightforward" to "simple-minded" In this context, the sense is the English phrase "single-minded" or, better, "focused." Double vision is a defect of the eye, a lack of focus. Single-vision good, double bad.

your -- The word translated as "your " is the genitive form of the singular, second-person pronoun, which is most commonly the possessive form. This pronoun follows the noun so "of yours."

whole -- The word translated as "whole" means "complete" and "entire," but it also has a number of other meanings including "the universe" and "speaking generally."

missing "the"  -- (MW) The untranslated word is the Greek definite article, "the." The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those"). See this article for more. 

body -- The first time the Greek word for "body" was used, it was generic. Here, it is specific, "your body" so the sense it gives is of an individual's physical life.

will -- This helping verb "will" indicates that the verb is the future tense. Helping or auxiliary verbs are needed to translate the Greek verb forms into English.

be -- The Greek word translated as "be" is the future tense of the common form of "to be." It appears at the end of the sentence.

full of --  (IP) There are no Greek words here that can be translated as "full of" nor is the concept part of the following word related to "light."

light. -- (WW) The Greek word translated as "light" is not the word for "light" but means "shining" and "bright." It is a combination of the words that means "light" and "shining." Since Jesus uses light as a metaphor for knowing, the term "bright" works well because in English it means "intelligent." However, there is also a sense of "successful" and "well-known," as we might say that someone has a "bright career" or is a "bright star" in their profession.  For more on the words used to mean "light" refer to this article. The final play on words is its use as a metaphor for seeing things clearly and distinctly, which makes perfect sense when talking about the eye or sight.