The anatomy of their eyes lets them see all around of their environment. Their eyes are attached into stalks which gives them the ability to have a 360-degree vision which is good for spotting potential prey but their vision is restricted though.
Hermit crabs are known to differentiate between colors and shades, but unfortunately not with different shapes.
Their other senses are more reliable though such as their scent, hearing, and touch. Excessive exposure to bright lights can cause distress to hermit crabs.
How Many Eyes Do Hermit Crabs Have?
A healthy hermit crab have 2 eyes. They dont shed their eyes like their limbs while stressed or undergoing molting. If in case that they have missing one of their eyes, make sure they are not sick or fighting with other hermit crabs in the tank.
As mentioned above, hermit crabs have sensitive vision, especially to excessive light exposure. Hermit crabs will go as extreme as sever their own eyestalks when they get exposed to excessive illumination. So take note of this.
Hermit crabs can also lose their eyes in conflict with other hermit crabs. This happens when they don’t have enough access to shells in their tank. Hermit crab will fight other hermit crabs for their shell. So if you’re caring for multiple hermit crabs, be sure they are provided with enough shells with variety of sizes and shapes.
If a hermit crab does lose their eyestalks they may or may not grow it back while in molting phase. It really depends on the extent of the damage to the eyestalk’s nerves and even if it does grow back there are no assurance that it will have working eyes.
How Good is Hermit Crab’s Vision?
A hermit crab’s eyes are like those of insects and just like their fellow invertebrates, hermit crabs have compound eyes as well. What does this mean? It means that their eyes are broken into tiny orbs also known as ommatidia.
And each of their eyes or ommatidia has their independent cornea, lenses, and photoreceptor cells. That said, this means hermit crabs have large range of vision for their small size. And this also helps them to tell the difference between lights and colors.
But as mentioned above, this does not always translate into a great vision compared to humans and mammals. Their compound eyes are not really meant to filter out detailed information about their vision. And according to studies, hermit crabs are having a hard time to recognize shapes by their sight alone.
Basically their vision is designed only for them to be able to survive in the wild but not really for other purposes.
Can My Hermit Crabs See in the Dark?
Hermit crabs are nocturnal animals which means they evolved to have a superior vision during night time. That said, in the captivity, hermit crabs prefer to have dim lighting. Again, DO NOT provide them bright lights as this can cause distress to them since their vision is very sensitive to excessive exposure to lights.
