Difference between revisions of Blur
Jump to navigation
Jump to search
m
→See Also
No edit summary |
m (→See Also) |
||
| (4 intermediate revisions by 2 users not shown) | |||
| Line 5: | Line 5: | ||
A normal healthy eye can experience blur by looking at images through lenses or mirrors that cannot be cleared by [[accommodation]]. | A normal healthy eye can experience blur by looking at images through lenses or mirrors that cannot be cleared by [[accommodation]]. | ||
A common description of blur is that it looks like [[wikipedia:Gaussian blur | Gaussian blur]]. | A common description of spherical (myopic or hyperopic) blur is that it looks like [[wikipedia:Gaussian blur | Gaussian blur]]. Note that spherical defocus can also cause double vision, not just blur. | ||
A good [[normalized]] creates some blur or double vision challenge for distant objects, but objects that are slightly closer are clear. A good [[differential]] creates some blur or double vision challenge near the ergonomic working distance. They should be determined by calculating [[diopter]]s and [[cm]], but a normalized is typically 20/20 to 20/50, and a differential is typically 20/40 to 20/150. | |||
{| class="wikitable" style="text-align:center;" | |||
! Amount of blur | |||
! Visual Acuity | |||
|- | |||
| none | |||
| 20/5 to 20/15 | |||
|- | |||
| tiny | |||
| 20/15 | |||
|- | |||
| little | |||
| 20/20 | |||
|- | |||
| some | |||
| 20/25 | |||
|- | |||
| a lot | |||
| 20/50 | |||
|- | |||
| a huge amount | |||
| 20/300 | |||
|} | |||
==Myopic vs Hyperopic Blur== | ==Myopic vs Hyperopic Blur== | ||
| Line 33: | Line 58: | ||
==Blur Adaption== | ==Blur Adaption== | ||
=== | ===Reduced Lens Blur Adaption=== | ||
“Blur Adaption” unfortunately has two meanings. The meaning commonly meant by Reduced Lens forum members is encountering so much blur that the visual system gives up. This is something like learned helplessness at the biological level. | |||
===Clinical Blur Adaption=== | ===Clinical Blur Adaption=== | ||
When a doctor uses the term | When a doctor uses the term “blur adaption” they mean that a person has adapted to perform visual tasks despite their blur. A common symptom is that the visual cortex perceives less blur than there actually is. This can happen with the reduced lens blur adaption, resulting in perceived visual acuity increases without actual axial reduction. | ||
==See Also== | ==See Also== | ||
| Line 45: | Line 70: | ||
*[[Chromatic Aberration]] | *[[Chromatic Aberration]] | ||
*[[Blur Horizon]] | *[[Blur Horizon]] | ||
*[[Double vision]] (Double vision is different from blur)<ref>https://endmyopia.org/the-giant-double-vision-thread/</ref><ref>https://endmyopia.org/reminder-tip-recognize-double-vision/</ref> | |||
*[[ | |||
==External sources== | ==External sources== | ||