On hot days, the air often feels thick and hazy, making it hard to see things clearly from a distance. This happens because heat causes the air to move and shift in uneven ways. When the ground gets very hot, it warms the air just above it, and this warm air rises. As it rises, it mixes with cooler air above, creating little pockets of air at different temperatures. These pockets bend light in different directions, which is why distant objects might look wavy or blurry.
Cool air, on the other hand, is more stable. When the temperature is lower, the air does not move around as much, and light travels through it in a straighter path. This means that things look sharper and clearer. That is why mornings, when the air is cooler, often feel crisper and easier on the eyes. Even a breeze of cool air can help settle the air and reduce the wavy effect you see on hot days.
Humidity also plays a role. Moist air can scatter light and add to the haze, but cool air usually holds less moisture, which helps improve visibility. So, when the temperature drops, whether at night or after a cool wind, the air feels cleaner and clearer. This is not just about comfort; it also means your eyes don’t have to work as hard to focus on distant objects.
In places like deserts or cities, where the ground gets very hot, the effect is even stronger. The glare and haze can make it hard to see, but a shift to cooler air can make a big difference. Even indoors, air conditioning can help by lowering the temperature and reducing the movement of air, which makes vision more comfortable.
Sources
https://smart.dhgate.com/why-is-air-invisible-understanding-atmospheric-transparency/
https://smart.dhgate.com/why-do-you-see-waves-when-its-hot-the-science-explained/
https://www.swfleye.com/blog/best-season-for-cataract-surgery-fall-benefits/
https://www.uoosd.com/ocean-and-desert-brightness
