What is the standard abbreviation for gram?

The standard abbreviation for gram is represented as "g." In the International System of Units (SI), "g" is universally recognized as the symbol for gram. This is important for clarity and consistency in scientific and medical contexts, ensuring that the measurements are easily understood and properly documented. The use of single letters as abbreviations is common in the SI system, which helps to avoid confusion that may arise from longer terms.

While "gm" is sometimes used informally or in certain contexts, it is considered less standard compared to the single letter "g." The abbreviation "gr" stands for grain, which is a different unit of measurement, and "gram" is simply the full word and not an abbreviation. Understanding these distinctions is key in the field of ophthalmology and other medical disciplines where precise measurements are crucial.