黑板同课桌椅一样,是基本的教学设备.一个学生每周平均至少有十五个小时面对着黑板,看着它上面的字迹.一个教师一年中同黑板打交道的时间,不少于四百小时.黑板的质量不仅影响教学效果,还对学生的健康——尤其是视力有密切的关系.我国广大农村学校,绝大多数使用水泥或木质黑板.这类黑板质量不是很好,如果教室采光又不够合理,不仅对比度不够,还容易产生眩光,学生看黑板上的字迹就不清楚,使他们的眼睛处于紧张状态,时间一长,就会产生视觉疲劳和精神疲劳,使视力下降,精神不集中,既影响健 The same blackboard as the desk and chair, is the basic teaching equipment.A student average of at least fifteen hours per week facing the blackboard, watching the writing on it.A teacher a year to deal with the blackboard time, not less than Four hundred hours.The quality of the blackboard not only affects the teaching effect, but also on the health of students, especially the eyesight is closely related to the vast majority of rural schools in our country use cement or wood blackboard.The quality of such blackboard is not very good, if Classroom lighting is not reasonable enough, not only the contrast is not enough, but also prone to glare, the students look at the blackboard writing is not clear, so that their eyes are in tension, over time, it will have visual fatigue and mental fatigue, decreased vision, Insanity, both affect the health