Close-up shots of spider eyes can be intriguing or downright scary, depending on who you ask. I personally find spiders fascinating creatures and am not disturbed or uncomfortable by their “scary” look, demeanor, or spider eyes.
I enjoy learning and reading about spiders and I imagine you do too since you are visiting this article (or at the least, you are curious about them).
This article gives you all the knowledge that you’ll ever need to know about spider eyes, what they are used for, and why they vary among species.
I will also discuss various species based on their eye count and why they have different amounts. Let’s get started!
How Many Eyes Do Spiders Have?
With over 34,000 different spider species found around the world, you can expect a little variety among the spiders. That variety can definitely be seen in spider eyes.
Even though most spiders have eight eyes that are arranged in pairs, some spider species have more eyes and some have fewer.
Some spiders have an odd number of eyes while others have no eyes at all.
Spider eyes are one of the many determining factors that are used to classify spiders and separate them into different groups or families.
Although most spiders have eight eyes, other spiders will have different eye counts based on their species, when they are active, and where they are found – along with other factors.
Why Do Spiders Have So Many Eyes?
Spiders don’t have the ability to turn their heads because they don’t have necks, so they rely on their extra eyes to detect things around them that they can’t detect with their front set of eyes.
Not all eyes are used for vision in the same way that other animals see and not all spiders use their eyes in the same manner.
Even though most spiders have eight eyes, they don’t have as good of eyesight as you might think they should.
Although spiders rely on some of their eyes to see to a certain extent, they also use other senses to detect vibrations and movements. So having the greatest vision isn’t a necessity.
It is a combination of all their senses that help spiders get through their (daily and nightly) life and routines.
Without the extra eyes and other heightened senses, spiders wouldn’t be able to see potential prey or spot a predator that is lurking outside their front peripheral.
Why Don’t Other Spiders Have 8 Eyes?
Spiders with no eyes are mainly cave-dwelling spiders. Since it is completely dark all the time, these spiders don’t need the ability to see inside the darkness of the caves.
Evolution formed their physical traits a long time ago and eyes were left behind to conserve energy and provide for other heightened senses more suited for a completely dark cave.
Other spiders with varying counts of eyes have evolved to suit their environments. Some use their eyes for better fields of view, some use them for night vision, and others use them for specific hunting purposes.
Spider eyes have varying degrees of use as explained in this article. But they all have evolved in a way that is best for the spider species and their survival in their environments.
Do Spiders Have Good Eyesight?
Jumping spiders have the best eyesight among the spider species. Even though most spiders have eight eyes and some have even more, their number of eyes doesn’t equate to better vision.
Most spiders’ eyesight is actually not that good at all. Spiders don’t see nor have they evolved to see the world as we humans see it.
Spider eyes are equipped with lenses that are better than photographic lenses in regard to image brightness.
But spider eye retinas have different photoreceptors than that of a human eye and image resolution is seen at much less degree and focus than what humans can see.
Spider Eyes During the Day
Spiders that hunt during the day not only use their eyes for vision but also use them for rapid movement.
This provides spiders with some advantages.
Having eyes that detect rapid movement gives the spiders the ability to quickly detect prey when they are hunting but also affords them the ability to react quickly to get away from predators when they are the ones being hunted.
Spider Eyes During the Night
Spiders that are active during the night use other eyes to detect dark and light intensity changes that signal to them when it is time to build their webs and get ready for nighttime hunting.
Net-casting spiders have two large eyes toward the back of their heads.
These large eyes give net-casting spiders the ability to have a wide field of vision but also provide them with low-light night vision capabilities.
But the majority of spiders don’t rely on having keen eyesight for their daily and nightly activities.
Do Spiders With More Eyes Have Better Eyesight?
Since not all spider eyes are used specifically for seeing, a spider with more eyes doesn’t mean better eyesight. Spiders use their eyes as information receptors and for the various evolutionary reasons listed above.
Some spiders have better eyesight than others, but their eyes aren’t designed to see the world better.
Their eyes are designed to provide them with the greatest ability to survive in their natural environment based on the way evolution decided for them.
Related Questions & Facts About Spider Eyes
Below are 12 common questions related to spider eyes including what spiders have no eyes, spiders that have an odd number of eyes, and spiders related to other eye counts.
1) How Many Eyes Do Wolf Spiders Have?
Wolf spiders have eight eyes. Two eyes are located on the top and side of their heads, two in the front, and four smaller eyes that are in a slightly curved row located just above their mouths and just below their two bigger eyes in the front.
Wolf spiders use their eight eyes for various tasks including using their eyes as an odometer and compass, tracking the movement of prey and predators, maintaining orientation, and calculating distance.
2) How Are Wolf Spiders’ Eyes at Night?
Wolf spiders have keen eyesight at night and can see much more light through their retinas because they have a reflective tissue called tapetum lucidum.
This tissue allows wolf spiders to take in more visible light through their retinas and increase the light available to their photoreceptors, which gives them the ability to see much better than most other spider species at night.
3) How Many Eyes Do Jumping Spiders Have?
Jumping spiders have four sets of eyes. They have two big eyes in the front which are their primary set of eyes and have retinas that can move (swivel).
They also have three sets of fixed secondary eyes that help detect movement from the sides and back.
4) How Many Eyes Do House Spiders Have?
The majority of spiders have eight eyes and that includes house spiders.
Their eyes are used for the processing of various tasks and to provide them with the tools needed to catch prey and get away from predators.
5) How Many Eyes Do Tarantulas Have?
Like most other spiders, tarantulas have eight eyes. Although they are bigger than other spiders, they still have eight eyes like most others.
6) What Spiders Have 10 or 12 Eyes?
While there is mention of spiders that have up to 10 or 12 eyes on many reputable websites like National Geographic, there is no known or verifiable information readily available about spiders with 10 or 12 eyes other than the mention that they exist.
So take that however you want. Maybe they exist or maybe we are being fed false information.
If someone knows of a spider species with 10 to 12 eyes that can be verified, please let us know and we will update the public on their existence.
7) What Spiders Have 8 Eyes?
The majority of spiders have eight eyes including:
- American house spiders
- Black widows
- Brown widows
- Grass spiders (depending on species)
- Hobo spiders
- Huntsman spiders
- Jumping spiders
- Orb weavers
- Wolf spiders
- Yellow sac spiders
8) What Spiders Have 6 Eyes?
Brown recluse spiders have six eyes, as well as some grass spiders.
Others with six eyes include cellar spiders and spitting spiders.
9) What Spiders Have 4 Eyes?
Spiders species that are part of the Symphytognathidae family have four eyes.
Some spiders in the Nesticidate family also have 4 eyes.
10) What Spiders Have 2 Eyes?
Some species of daddy longlegs or daddy long legs (as they are often called) only have two eyes. They are a part of the Pholcidae family.
Although there is debate if they are really even spiders since they are more closely related to scorpions.
Other spiders that only have 2 eyes belong to families of spiders such as Diplogena, Medionops, Orthonops, Tarsonnops, and several others.
11) What Spiders Have No Eyes?
The first recorded huntsman spider without eyes was found in 2012 in a Laotian cave. The name of the species is Sinopoda scurion. As you may have guessed, this spider species lives in a dark cave habitat and are blind (well, obviously).
Another blind spider species that has no eyes is the Adelocosa anops – also known as the Kaua’i cave wolf spider. This species is mainly found in three caves off the coast of Hawaii on the Kaua’i island.
Spiders that live in dark caves will either be blind or have no eyes at all.
12) What Spiders Have an Odd Number of Eyes?
Spider species in the Caponiidae family have varying eye numbers as well as other physical features that are different from other spider species.
In some species of the Caponiidae, their paired eyes meet in the midline giving them an odd number of eyes. This includes Calponia and Caponia species.
Calponia species are known for having a species named after Harrison Ford called the Calponia harrisonfordi.
Not a lot is known about these spiders but it is believed that they hunt and eat other spiders.
To recap, not all spider species have the same number of eyes but the majority of spiders have eight eyes to help them see and detect the environment around them (including potential prey and predators).
More spider eyes don’t necessarily mean better eyesight and not all spider eyes are used for vision.
Spider eye counts vary and some spiders can have as many as ten to twelve eyes (although not confirmed), an odd number of eyes, or no eyes at all – depending on where they live, when they are active, and other determining factors.
Thank you for visiting and reading this article. I hope I was able to give you the knowledge you were seeking about spider eyes – why they have so many and how they are used.
If you enjoyed this article, please check out some of our other spider articles about spider body parts.