完全失明：失去视力的人有不同的经历。有人描述看到完全黑暗，就像在洞穴里一样。有些人看到火花或经历生动的幻觉，可能采取可识别的形状，随机的形状和颜色，或闪光的形式。 “愿景”是Charles Bonnet综合症（CBS）的标志。 CBS可能是持久的或短暂的。它不是精神疾病，与脑损伤无关。除完全失明外，还有功能性失明。功能性失明的定义因国家而异。在美国，它指的是视觉障碍，用眼镜进行最佳矫正的视力较好的眼睛比20/200更差。世界卫生组织将失明定义为将最佳眼睛的视力矫正至不超过20/500或视力低于10度。功能失明的人看到的取决于失明的严重程度和损伤的形式：法律盲目：一个人可能能够看到大型物体和人，但他们没有焦点。法律上失明的人可以看到颜色或在一定距离处看到聚焦（例如，能够计算在脸部前方的手指）。在其他情况下，颜色敏锐度可能会丢失或所有视力都是模糊的。经验变化很大。具有20/400视力的乔伊告诉ThoughtCo他“经常看到总是在移动和改变颜色的霓虹斑点。”
加拿大渥太华护理Essay代写：功能性失明
Total blindness: People who lose sight have different experiences. Some people describe that it is completely dark, just like in a cave. Some people see sparks or experience vivid illusions that may take recognizable shapes, random shapes and colors, or flashes. The Vision is the hallmark of Charles Bonnet Syndrome (CBS). CBS may be permanent or short-lived. It is not a mental illness and has nothing to do with brain damage. In addition to complete blindness, there is also functional blindness. The definition of functional blindness varies from country to country. In the United States, it refers to visual impairments, and better-corrected eyes with glasses for better correction are worse than 20/200. The World Health Organization defines blindness as correcting the best eyesight to no more than 20/500 or less than 10 degrees of vision. The blindness of people who see it depends on the severity of the blindness and the form of the injury: legal blindness: a person may be able to see large objects and people, but they have no focus. A person who is legally blind can see the color or see the focus at a certain distance (for example, can calculate the finger in front of the face). In other cases, color acuity may be lost or all vision may be blurred. Experience has changed a lot. With 20/400 vision, Joey told ThoughtCo that he “always sees neon spots that are always moving and changing colors.”