|Hyperopia and myopia are also called far sightedness and near sightedness. In hyperopia people have difficulty in seeing near objects but can see the far objects clearly whereas in myopia people who have difficulty in seeing distant objects but can see near objects clearly. In color blindness the people having difficulty in viewing red, blue, green or mixture of these colors. It is caused due to absence or malfunction of certain color-sensitive cells in the retina.
A journal is a periodical publication intended to further progress of science, usually by reporting new research. Most journals are highly specialized, although some of the oldest journals publish articles, reviews, editorials, short communications, letters, and scientific papers across a wide range of scientific fields. Journals contain articles that peer reviewed, in an attempt to ensure that articles meet the journal's standards of quality, and scientific validity. Each such journal article becomes part of the permanent scientific record.