The moon illusion is the optical effect where the full moon appears larger when it's near the horizon than when it's high overhead.

The atmosphere could act like a giant lens, magnifying the moon as it rises and sets, but this explanation doesn't work because the atmosphere's refraction would actually make the moon look slightly smaller, and measurements show the moon's size doesn't change.

The Ebbinghaus Illusion is where two identical objects look different because of the relative size of the objects they're surrounded by.

The Ponzo Illusion is when objects near the horizon are perceived as larger because our brain compensates for perspective, making the closer object seem smaller and the one near the horizon larger, even if they are the same size.

The most promising explanation today is known as Convergence Micropsia.

The Ebbinghaus and Ponzo illusions are inadequate for explaining the moon illusion because there are situations where the moon illusion persists despite conditions that should negate these effects. For instance, pilots flying high above the clouds without nearby objects for comparison still experience the moon illusion, which contradicts the Ebbinghaus Illusion. Similarly, the Ponzo Illusion doesn't hold up in planetariums, where the moon illusion doesn't occur even with a simulated horizon. Additionally, the moon illusion disappears when looking at the moon between one's legs, which cannot be explained by these illusions alone.

Two experiments you can perform to test the explanations offered are:

1. For the Ebbinghaus Illusion, you could observe the moon when it's near the horizon with objects like trees and buildings in view and then compare it to the moon's appearance when flying in an airplane high above the clouds, where no such objects are present.
2. To test the Ponzo Illusion, you could go to a planetarium and observe a simulated moon near the horizon on the dome and see if the moon illusion occurs in the same way as it does when looking at the actual night sky.

To solve the mystery of the moon illusion once and for all, it would require a definitive explanation that accounts for all observations and conditions under which the illusion occurs, including those that contradict current theories like the Ebbinghaus and Ponzo illusions. This explanation would have to be consistent with the experiences of pilots and sailors who see the illusion without nearby objects, and it would need to explain why the illusion doesn't occur in planetariums or when looking at the moon upside down between one's legs. It would likely involve a comprehensive understanding of human perception and the brain's interpretation of visual stimuli in various contexts.

最初关于大气层像巨大的透镜一样放大月亮的解释被认为是错误的 ， 因为如果考虑大气折射的话 ， 实际上会使月亮看起来稍微变小 。 此外 ， 如果你实际测量月亮在不同位置时的可见大小 ， 你会发现它根本没有变化 。 因此 ， 这个解释并不成立 。

聚焦微视解释认为 ， 当月亮在地平线附近时 ， 我们的眼睛需要向外转动（发散）以聚焦在远处的月亮上 ， 而当月亮高挂天空时 ， 眼睛转动（收敛）的程度较小 。 由于在日常生活中 ， 眼睛向外转动通常与观察较远的物体相关 ， 我们的大脑可能会因此而将地平线上的月亮感知为更大 。 然而 ， 这一理论并没有广泛地被接受 ， 因为它不能解释在没有任何地平线参照物的情况下 ， 人们仍然会经历月亮错觉 。

月亮错觉在行星馆内不显著的现象表明 ， 这种错觉可能与真实的地平线环境中的视觉参照物有关 ， 而不仅仅是大脑对于物体大小的自动校正 。 因为在行星馆内 ， 尽管天空和地平线都被展现在球形穹顶上 ， 但这种设置没有复制真实世界中的所有视觉线索 ， 这可能意味着月亮错觉需要更复杂的环境因素才能出现 。

自然界中还有其他的错觉 ， 例如幻日 、 幻月 、 绿闪 、 沙漠中的海市蜃楼 、 以及因大气折射导致的星星闪烁等现象 。 这些错觉通常都与大气层中的光线折射有关 ， 它们可以改变我们对天体和远处物体的视觉感知 。