There have been many questions of moving, floral animals, most of these focus on their intelligence, but what about their sense of sight. I fail to understand how a botanic based alien would be able to see, theoretically they could evolve them from the very start as light patches, like animals did, but I would rather not cop out like that. How can I explain how my botanic aliens sense of sight works?

Previous Questions



Next Question


  • 1
    $\begingroup$ Just saying, until you solve the problem of immediate, complex motion, plants with eyes won't be very different from plants with trigger hairs like Venus fly trap, since it only has a few actions to taken in response to the stimulus. (From how it appears on your "Muscles" question, that problem is still unsolved) $\endgroup$
    – Luna
    Dec 16, 2016 at 18:12
  • $\begingroup$ Depends on what you mean by "see". If this requires actually forming an image from light, then you can't go around developing entire eyes. $\endgroup$
    – Feyre
    Dec 16, 2016 at 18:13
  • 1
    $\begingroup$ In addition to Feyre comment: if they don't have to see the exact pictures, their current sense of sight would probably suffice, they can even differentiate wavelengths : en.wikipedia.org/wiki/Plant_perception_(physiology)#Light $\endgroup$
    – user8808
    Dec 16, 2016 at 18:22
  • $\begingroup$ Eyes have evolved so many times that it is not a stretch to think plants would evolve them if they had a use for them. Even animals started with a light sensitive reaction. After that it just about making a better image. $\endgroup$
    – John
    Dec 16, 2016 at 18:51
  • 2
    $\begingroup$ theoretically they could evolve from scratch ... but I would rather not cop out like that Short of evolution, I'm not sure what else to offer; it's not really clear what you want to happen to make these eyes if evolution of eyes is not allowed. $\endgroup$
    – Zxyrra
    Dec 17, 2016 at 5:04

3 Answers 3


Current plants already react to light; every plant will "seek out" light by growing their shoots towards a light souce, and grow roots in the other direction. You can see it yourself if you grow plants indoors, how they will apear to lean towards windows as they grow. Plants can react even faster, with sunflowers slowly rotating as the sun progresses across the sky, or flower blooms opening during the day and closing at night. Carolus Linnaeus proposed a Horologium Florae made of beds of fourty-three types of flowers that would open and close at different times of day, like a sundial of blooms.

The mechanisms are there, corresponding to the light-sensitive patches of skin on animals. You could use mad science to make these processes more efficient (along with the rest of the plant metabolism so it can react at animal-like speeds), or a lot of time and environmental handwavium for encouraging light-sensing traits in plants. Animals improved their light-sensing by having a polyp half-covered in sensors and a small aperture, using part of their meat as a pinhole-camera; it's very efficient for not much expense so I'd expect the same mechanism in other creatures that will have distance vision. A plant with a pinhole-camera pod would have a much better time of it with a focusing lens, as it would resolve fine detail faster and with a smaller pinhole-pod, and the lens can physically close the pinhole keeping the pinhole-pod clean of dust or other opaque substances that would cover the light-sensitive parts. Perhaps the first lenses would be a drop of water, as they're very transparent and flexible, later evolving to a transparent sap that will hold its shape and less likely to evaporate.

Now, where's the organ that collects this sensory data and turns it into perception? and does it quickly? That's the real thistle of the puzzle.


Well plants are already covered with light sensitive molecules: chlorophylle.

You could easily imagine this evolving into a multi faceted eye like the flies except they could see from everywhere.

You could even consider a weakness which their enemies/predators could use: they could be blind to anything underneath them. Which they may have fixed with sensing whiskers for their locomotion.

  • $\begingroup$ Chlorophyll is a pigment vital to photosynthesis. How would this evolve into eyes. $\endgroup$
    – Feyre
    Dec 16, 2016 at 18:33
  • 1
    $\begingroup$ becasue not every cell in a plant engages in photosynthesis. $\endgroup$
    – John
    Dec 16, 2016 at 18:49

Purpose of sight

It's worth considering that the only reason why animals have eyes is that they can an do take useful actions in response to what they see.

Many current plants have an ability to sense light, direction of light and (for example) track the sun throughout the day - this is the limit to what their eyesight is useful for them. Being able to observer rapid changes in light is not useful if the plant cannot react rapidly, so such an "eye" would be removed by evolution and replaced with something "cheaper". Gaining an accurate picture is not useful if the plant either isn't able to act or react with such accuracy, or can do it by iterative refining, slowly growing towards something.

In essence, if a plant has powerful eyesight and a visual cortex that's able to track moving objects, then that's a strong indication that the plant is capable of rapid and accurate movements to react to those moving objects, unlike the plants of our world, otherwise these eyes make no sense - they would/could evolve after a mobile or active plant, so there would/could be some mobile/active plants that are nearly blind (just photosensitive), but there would be no stationary plants sitting and looking around.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .