At some point in your life, you might have made a quick trip to the kitchen in the middle of the night. When you opened the refrigerator, you were able to see your snack options clearly thanks to the handy refrigerator bulb. But when you checked the freezer, there was no light, and you fumbled in the dark. In case you are wondering why refrigerators have a light while freezers don’t, we have some surprising answers based on the history of this appliance.

According to Cornell University professor of economics, Robert H. Frank, the cost-benefit principle is the most probable reason why manufacturers leave out the freezer light. Basically, since freezers get opened less compared to refrigerators, the cost of adding a light in the freezer outweighs its benefits. And since the cost of putting a light in the freezer is the same as that for the refrigerator, manufacturers forgo the former to bring the production cost down.

Refrigerator technician Ed Dougherty has echoed the same sentiment, saying, “People don’t open the freezer nearly as much as they open the refrigerator and certainly not as much for ‘browsing'” (per Today I Found Out). So, it makes sense that customers would expect their fridge to be brightly lit, but be less picky about the freezer.

In addition to the cost-benefit principle argument, ice crystal buildup is another factor manufacturers consider when deciding not to equip freezers with a light. Apparently, older non-automatic defrosting models would form ice crystals when humid air entered every time the door was open. Having a light would only benefit you if you planned to open the freezer often (and keep it open) — so this did not make much sense.

It’s also worth noting how older incandescent bulbs used by refrigerator manufacturers generated heat when turned on. Putting one in the freezer could cause problems since a hot glass bulb could create condensation or partially thaw nearby food items when the door is open. Then, there’s the risk of the bulb shattering when repeatedly heated and cooled. Of course, some may argue that modern appliances  like these highly-rated refrigerators make use of LED lights. However, since consumers have already grown accustomed to not having a light in the freezer, manufacturers may not have a compelling reason to make the switch.

Finally, freezers are often more densely packed than refrigerators, especially when stocks have just been replenished. Thus, putting in a light bulb would not make a big difference since it won’t be able to illuminate most of the freezer when it is blocked by the food items.

The absence of light is not the only distinguishing feature between a fridge and a freezer. Most refrigerators come with convenience features you won’t find in freezers. For instance, fridges have adjustable shelves, door bins, and crisper drawers. These help you group and organize the food and drinks you store inside the appliance. Each compartment may have a different temperature since the cold air would have to travel through the partitions to circulate. By adopting a smart way to organize your fridge using these components, you can ensure your food never goes to waste. On the other hand, compartments are unnecessary in freezers since they need to maintain a single temperature throughout.

Another distinction refrigerators have over freezers is the labeled storage spaces for eggs, butter, and tall drink containers — items that are never stored in freezers since they are not meant to be frozen. These compartments are typically found on the inside wall of the refrigerator doors.