An example of MS-DOS's command-line interface, this one showing that the current directory is the root of drive C. MS-DOS (/ËÉmÉsËdÉs/ EM-es-DOSS; acronym for Microsoft Disk Operating System) is a discontinued operating system for x86-based personal computers mostly developed by Microsoft.
Written by: Kierstan Boyd. Nov. 08, 2012. The main symptom of vitamin A deficiency is vision loss and blindness. Vision loss often begins as a problem adjusting to seeing in the dark, or night blindness. People with night blindness do not see well in the dark, but are able to see normally if enough light is present.
Low levels or lack of Vitamin A in a human body causes Vitamin A deficiency and it is the number one cause of what is known as preventable blindness in children and severe visual impairment.reatment of Vitamin A Deficiency. Vitamin A deficiency can be treated if the state has not worsened for which early diagnosis matters a lot. 1  A diet which is rich in Vitamin A is usually the treatment and the best prevention method of vitamin A deficiency.