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→Insights about Transient Astigmatism and Cylinders
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=== Insights about Transient Astigmatism and Cylinders === | === Insights about Transient Astigmatism and Cylinders === | ||
Well, it looks like cylinders ruin everything. From what I can see, there are 2 mechanisms: the eye itself shrinks and grows based on defocus, and then visual perception changes, but it can only adapt to gradual changes. That's why blur adaptation is bad, as the axial length and visual perception go out of sync, later leading to lots of accommodation to "simulate" myopia when making the light input match visual perception's requirements | Well, it looks like cylinders ruin everything. From what I can see, there are 2 mechanisms: the eye itself shrinks and grows based on defocus for emmetropization, and then visual perception changes, but it can only adapt to gradual changes. That's why blur adaptation is bad, as the axial length and visual perception go out of sync, later leading to lots of accommodation to "simulate" myopia when making the light input match visual perception's requirements. | ||
Simple binocular spherical changes are very easy to adapt to, since they just "navigate" the focal planes. | If you stop using glasses, your eye's axial length adjusts, but the visual system doesn't care. It'll still think your vision is distorted. | ||
Whenever a cylinder is changed, the eye compensates for it, affecting all later focal planes. Equalizing seems to change the offset between eyes when navigating the focal planes. When undoing the changes, after you hit the cylinder change point, it applies the cylinder to the entire focal plane, and then you have to fix it for the nearer focal plane before continuing to reduce. Because it'll be "too hard" to adapt to too many changes, that's why it's better to resolve the cylinder at closer focal planes before continuing. | |||
Simple binocular spherical changes are very easy to adapt to, since they just "navigate" the focal planes. Jumping 1.5 diopter is quite easy to adapt to, compared to adjusting offsets (equalizing). | |||
It's interesting how our visual system can compensate for cylinder and spherical distortion. | It's interesting how our visual system can compensate for cylinder and spherical distortion. | ||