Your eyes say all the words that your mouth couldn't

Hello folks who wonder if there should be a pop quiz before people cast their vote to see how informed they are,

Of all our senses, nothing works overtime as much as our sense of sight only to be overcome by our sense of taste when we are stuffing our mouth with cheesecake and ice cream because of the recent breakup or on hearing the news that your favorite tv series is not going to be renewed for a new season.

If you have ever seen the inner workings of a mechanical watch (a type of watch people used to wear before smart watches flooded the market), you will see it as a complex operation with over 400 parts that ultimately helps the user tell how much time they have not been looking at their phone today. Eyes, despite how simple they look on the surface, have over 2 million parts that allow the user to see if there is a difference between a 4k and 6k video on YouTube of a person reviewing different Halloween candies.

Arthropods like spiders who weave webs to capture prey do not have good eyesight and will majorly rely on their highly sensitive hairs that cover their bodies that pick up vibrations to warn of incoming threats or an unsuspecting prey caught in the web. Below is a Western Black Widow showing us its moves.

Jumping spiders got inspired by all the young adults travelling around the world and posting their photos in the picture-perfect locations all the time on social media, decided the web life was not for one whose heart seeks adventure. So, they decided to be constantly on the move and scout for food on the go. Developing good eyesight was key to their survival and while they were on it, they took inspiration from the Pixar movies to shape their eyes. Below is how a jumping spider would look at you in the wild.

And that is where it would have ended if people ever showed you jumping spiders in the wild. Not over here, not on my watch. Unlike the eyes on other spiders that simply help them to detect light from dark situations, the jumping spider possesses a sophisticated eye system. Here is what it looks like up close at all 8 of its eyes.

In terms of appearance all the eyes look similar in size albeit a few sizes here and there but the eye number 4 and 5 are the biggest eyes on this spider. When you look at it, it gives you the same feeling as seeing a puppy drenched in the rain. You just want to rescue it, dry it up and milk it for some Instagram hearts.

Eye no. 4 & 5 are referred to as the primary eyes. All the other eyes are secondary eyes and are used to detect movement around the spider. This movement can be a predator or a meal walking around or even their favorite Taco truck setting up shop on a Tuesday. The primary eyes are then used to observe details on that predator, prey or the menu on the Taco truck. So anytime there is a sudden movement, the spider will turn in that direction to let the primary eyes get a closer look. Similar to how you would use your regular eyes to see some birds, then on locating them use your binoculars to focus in on them.

But unlike you who is just looking at birds just for the fun of it, the spider has no time for fun. It needs to not only focus on the details of the prey but also judge the distance it is from the spider if it is going to pounce on it or sneak up on it. Just how you would adjust the focus on your binoculars if the bird flew close to you from its original position, the spider does something similar.

If you ever look at the top of a jumping spider, you will see something moving in its head like the one below.

That is the spider adjusting its internal focus to get a better look at the object in front of it. But it does not stop there, these spiders also need to determine the distance the prey is from its location. To determine that they will keep one eye with the target in focus and change the focus of the other eye to determine the distance of the target. If you ever had to scroll the binocular focus knob a lot you know the bird is far away, and deduce it is close once you start to gradually turn the focus knob. Below is an example showing my trusty co-pilot (the name is Jake the fox if you are curious) with how it might look to the spider.

Anytime one of the eyes is out of focus, it will be apparent. Since one of the eyes will be black colored and the other eye will switch between black and honeycomb colored.

And now you know how it catches its meal, let's see one real world example. For anyone who has a soft spot for Green Lacewing larva (Don't know why they are so awesome, read this post), it would be a good time to stop reading the post. Rest of you, chug along. Here is the larva just looking for some breakfast muffins lying around in a neighborhood park.