In visual perception, the<unk>  is the closest<unk>  at which an object can be placed and still form a focused image on the retina, within the eye's accommodation range. The other limit to the eye's accommodation range is the far<unk> . A normal eye is considered to have a<unk>  at about for a thirty year old. The<unk>  is highly age dependent (see accommodation). A person with hyperopia or presbyopia would have a<unk>  that is farther than normal. Sometimes,<unk>  is given in diopters (see ), which refers to the inverse of the distance. For example a normal eye would have a<unk>  of .
Near point
Mange
K-space 
MedCity 
Relative value unit
Trigger zone
Everywhere at the End of Time
Sense