Best corrected visual acuity characteristics measuring device, best corrected visual acuity characteristics measuring method, contrast sensitivity measuring device, contrast sensitivity measuring method, and contrast sensitivity target displaying device

A method for measuring best corrected visual acuity characteristics comprising:

• a step in which a refraction correcting part corrects the refraction of an eye to be examined of a subject based on corrected visual acuity data of said eye;
• a step of displaying a target to said eye through said refraction correcting part;
• a step in which an adjusting state measuring part measures whether said target is in the adjustable range of said eye;
• a step of correcting a corrective value for said refraction correcting part so that said eye can achieve best correction based on a result of measurement by said adjusting state measuring part, and
• a step of measuring visual acuity characteristics of said eye at a corrective value for said refraction correcting part to achieve said best correction of said eye according to responses of said subject about displayed targets.

A device for measuring contrast sensitivity comprising:

• a refraction correcting part for correcting refraction of an eye to be examined of a subject;
• a contrast target display part for displaying contrast targets;
• an adjusting state measuring part for measuring whether a contrast target is in the adjustable range of said eye when said eye looks at said target displayed in said contrast target display part through said refraction correcting part,
• corrective value correcting means for correcting a corrective value for said refraction correcting part so that said eye can achieve best correction based on a result of measurement by said adjusting state measuring part, and
• a contrast sensitivity determining part for determining contrast sensitivity according to responses of said subject about contrast targets displayed through said refraction correcting part corrected by said corrective value correcting means.

A method for measuring contrast sensitivity comprising:

• a step in which a refraction correcting part corrects the refraction of an eye to be examined of a subject based on corrected visual acuity data of said eye;
• a step of displaying a contrast target to said eye through said refraction correcting part;
• a step in which an adjusting state measuring part measured whether said contrast target is in the adjustable range of said eye;
• a step of correcting a corrective value for said refraction correcting part so that said eye can achieve best correction based on a result of measurement by said adjusting state measuring part, and
• a step of measuring contrast sensitivity of said eye at a corrective value for said refraction correcting part to achieve said best correction of said eye according to responses of said subject about displayed contrast targets.

A device for displaying contrast sensitivity targets comprising:

• a refraction correcting part for correcting refraction of an eye to be examined of a subject;
• a contrast target display part for displaying contrast targets;
• an adjusting state measuring part for measuring whether a contrast target is in the adjustable range of said eye when said eye looks at a target displayed in said contrast target display part through said refraction correcting part;
• a contrast sensitivity determining part for determining contrast sensitivity according to responses of said subject about displayed contrast targets, and
• corrective value correcting means for correcting a corrective value for said refraction correcting part so that said eye can achieve best correction based on a result of measurement by said adjusting state measuring part,
• wherein said contrast target display part is configured to display contrast targets to measure contrast when said contrast target is judged to be in said adjustable range of said eye by said adjusting state measuring part.