It is because the letters makes The Eye reflect back into the chart
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Just draw a couple of ray diagrams through a positive lens and you will see that a real image has to end up inverted, just like the image in your eye, which your brain then sorts out to a right-way-up image.
The visibility of objects in a mirror relates to two considerations: the physics of light itself, and perception in the eye-brain system. Because light reflects off such a reflective surface in a consistent manner (light travels in straight lines, and angle of incidence equals angle of reflection) its possible to perceive continuities in reflected light. This would not be possible if light was highly scattered or very diffuse, objects could not be perceived. The brain perceives reflected light as if objects were present because of mechanisms in the brain which interpret images received by the eyes the same way from a mirror as from an object outside a mirror, particularly including perception of depth and distance. Hence the brain would perceive an object in the direction of the mirror , although for example in a plane mirror they might seem laterally inverted.
It burns your eye
It is called the eye of the tornadoAn eye
Human eye cannot estimate speed because planes are too fast for an eye to estimate speed.
My wife would memorize the letters of the Snelling eye chart.
During an eye exam, the doctor asked the patient to read the letters on the sixth line of the chart.
An eye examination that determines sharpness of vision, typically performed by identifying objects and/or letters on an eye chart
The cornea and lens of the eye form a real, inverted image on the retina.
The inferior oblique muscle of the eye, abducts, elevates and laterally rotates the eye
When Dr. Spyglass gives you an eye exam, he points to letters on the chart. Each time, pick the symbol that points the OPPOSITE way (backward E instead of E, M instead of W) so that you get all of the answers wrong. This shows him that you are a friendly spy.
Typically, the eye chart is the Snellen chart.
inverted
The inverted or upside-down image is formed on the retina.
If you are referring to Snelen Eye chart it is very easy. all you have to do is to put the snelen eye chart on the wall, walk 20ft away from the chart then read it with your left eye closed then followed by your right eye.
Superior Rectus allows you to look Up & In, whiel the Superior Oblique allows you to look Up & Out.
we do get inverted image at the ratina. But this inverted image itself is being treated as errected by our mind.