Why do my glasses make the ground look tilted? I just started wearing glasses to correct my myopia today. I have -0.25 spherical and cylindrical power in my right eye and -0.5 spherical and -0.25 cylindrical in the left eye. Everytime I look at the ground, it looks tilted. The left hand side of the ground seems closer than the right. Why is this happening?
Is it because each lens has a different image distance and the brain not being used to these glasses yet, makes this mistake while mixing the image from both eyes together? Or is this something related to the glasses themselves and will persist?
 A: A cylindrical shape error in your eyes' lenses will tilt your horizon, but your brain gets used to that over time and your horizon seems level to you. When you put on the corrective lenses, this upsets the accommodation that your brain had learned to use and now the horizon seems tilted the other way. This too will go away with time.
As an example of how your brain can relearn the mapping of your visual field, you can put on prismatic glasses that flip your visual field upside down and in a matter of weeks, your brain will learn how to flip the image around so you can safely walk down the street even though you are seeing things upside-down. Then if you take those glasses off, everything looks upside down to you even though it isn't and it takes time for your brain to unlearn what you taught it with those glasses.
As an aside, the actual image of your visual field as projected onto your retina by the lens in your eye is upside down and reversed left-for-right, but the image as mapped into your perception of the world by the visual cortex and the nerve pathways between your retinae and the brain sort all of that out for you automatically.
