abstract background and aim: consider ing based on the presence or absence of swelling of the optic disc, optic neuritis classified nto two types of anterior and retrobulbar optic neuritis. the aim of this study was to compare the visual functions of patients with anterior optic neuritis and retrobulbar optic neuritis. materials and methods:this cross-sectional study was conducted in 48 patient...

Five thousand one hundred and twenty-nine Wisconsin children, ages 4–12 years, were tested for colorvision deficiencies using a newly devised, precisely calibrated paper-and-pencil test. The disposable 1-page test consisted of 1 demonstration and 8 test panels. Thousands of copies of the test were produced, and they were distributed and administered in classrooms by teachers. Children wrote dir...

We owe the first accurate description of color blindness to the chemist John Dalton, who in 1798 characterized his own condition in the words 'persons in general distinguish six kinds of colour in the solar image; namely, red, orange, yellow, green, blue, and purple.... To me it is quite otherwise:-I see only two, or at most three, distinctions. These I should call yellow and blue; or yellow, b...