Note the different forms, which differ in two respects: simplified does not have a left vertical stroke, while the traditional form has a left vertical stroke; and in simplified form, the top component is connected with the bottom, while in traditional they are separated – this last difference is shared with the related character 真 and the unrelated character 具. The traditional form and stroke order are used in Japan and Taiwan.
Oracle bone script: Ideogrammic compound (會意): 目(“eye”) + 丨(“vertical stroke”) – vertical stroke above the eye; looking straight ahead.
The line on the side appears in bronze script and subsequently stretched under the 目 shape, while the traditional form appears in seal script. The top component has been relatively unstable, taking on other shapes such as 匕 – compare 眞, and different forms of 真.