Have you ever wondered what your dog sees when they gaze up at you, or at least the treat in your hand?

Well, now you can find out, as a new interactive tool shows you how your pooch, and other pets, perceive the world around them.

Dogs, cats, birds and rabbits all have different eyes to humans, meaning they have a different field of vision and access to a different colour spectrum.

The new feature allows you to upload or take a photo, and then place a filter over the top to transform it into what your animal of choice would see.

At the back of the human eye are photoreceptors - cells that respond to the light shining in - and those used to detect colour are called 'cones'.

Dogs see in different colours to us because they only have two types of cones, whereas humans have three.

The photoreceptors used for motion and night vision are called 'rods', and dogs' retinas are rod-heavy which is why they can see better in the dark and can detect motion a lot better than humans.

Dogs' eyes are also positioned at a 20-degree angle, which increases their peripheral vision.

However, this also means that they can't see things as 3D as humans, thus reducing their depth perception.

At the back of the human eye are photoreceptors - cells that respond to the light shining in.

These come in two types, 'rods' or 'cones', and while rods are sensitive to motion and night vision, the cones that are able to detect colour.

Humans have three types of cone cells, and each of these are most sensitive to a particular colour, either red, green or blue. 

Dogs only have two types of cones which are sensitive to blue and yellow, meaning they can only see these colours as well as shades of grey.

This is comparable to the roughly nine per cent of people with red-green colour blindness, which makes green look more red.

However, dog retinas are rod-heavy, which is why they can see better in the dark and can detect motion a lot better than humans.

Dogs' eyes are also positioned at a 20° angle and are a lot further apart than ours, which increases their peripheral vision.

This gives them a 240° field of vision - larger than a human's 180° - but means they can't see things in 3D and have reduced depth perception.

What dogs lack in vision they more than make up for with their other senses, like their sense of smell.

Their 'olfaction' is between 10,000 to 100,000 times more acute than ours, so are still able to cope well if their vision deteriorates.

Animals, including humans, have a variety of complex structures in their eyes which allow them to see.

The pupil contracts to limit how much light is allowed in, much like a camera lens.

Most animals have both cones and rods in their eyes, which are called photoreceptors and are found in the retina.

Cones allow people to see colour and rods are sensitive to low-light levels which allows for a grey scale between black and white.

These photoreceptors are triggered by light and then this produces an electrical signal as they change shape.

Electrical signals are then carried to the brain via the optic nerve.

Signals from both optic nerves are then brought together by the brain at a point called the optic chiasm where the brain compares the two images.

This is what gives animals an understanding of depth and how far away objects are in their field of vision.

Like dogs, cats aren't thought to be able to see the full range of colours humans can see, with scientists saying they can mostly only see blue and grey.

To compensate for this, they are vastly superior at detecting motion, thanks to their 200° field of vision and greater degree of peripheral vision.

Cats also have excellent night vision, thanks to them having up to eight times more 'rod' photoreceptor cells, which are sensitive to low light levels.

However, felines do not see as well in bright light as they have ten times fewer cone cells than us, so it makes things look more blurry.  

Rabbits, on the other hand, have a nearly 360° field of vision due to having their eyes on the side of their heads, but they do have a blind spot directly in front of them.

They therefore rely more heavily on their acute sense of smell, but also use their whiskers and teeth to help 'see' what's directly ahead.

The hopping mammals also have two colour vision, limited to green and blue, and can only see in two dimensions at close ranges.

Their world appears grainy, but they can see better in the dark than humans as they have more rod cells.

Birds can see the whole spectrum of colours that humans can, but also a few extra ones that are invisible and inconceivable to us.

That's because they have four types of cone cell, and their extra one enables them to see wavelengths of light in the ultraviolet range, rather than just visible.

Species of birds which have their eyes on the side of their head have a field of vision of about 300°, whereas for those with them on the front, like owls, it is around 150°.

Some also can utilise 'monocular' vision that allows them to focus their eyes on different objects at the same time, rather than 'binocular' vision where both focus on the same object simultaneously.

The new tool was developed by global pet and house-sitting site TrustedHousesitters, and can be accessed here.

If you are using a mobile, you can also click here to open the feature through Instagram.

Angela Laws, community manager of TrustedHousesitters, said: 'The bond we share with our pets is so special, and truly understanding how they perceive the moments and life we share with them makes that bond even stronger.

'We created this tool to allow people to learn more about pet vision - from understanding your pet’s favourite colour to realising how they see you, it can give owners a newfound understanding of their best friend - furry or feathered.'

Goldfish 

Bubbles' memory might not quite be up to our capacity, but her vision offers her a far wider look at the electromagnetic spectrum.

Among the extra colours that goldfish can see are those in the ultraviolet — an ability which helps the fish to see in water.

They also possess literal fish-eye lenses — sporting round corneas that can gather light from a nearly 360° canvas and are the same density as water, as to compensate for how the liquid medium distorts light passing in and out of it.

Snakes

In games of dice, snake eyes are typically unlucky — and, in the daytime, pet serpents are similarly disadvantaged, having poor vision.

On the upside, some snake species have infrared vision, which can be combined with the senses received from its so-called pit organs — membranes lying between its eyes and nostrils — to create something akin to thermal imaging.

Snakes also have no eyelids. Instead, they sport a protective membrane that works somewhat like a contact lens, and is renewed — along with the rest of their skin — when they shed.

Chameleons

While perhaps more famous for mimicking colours than seeing them, chameleons have eyes that are almost all 'cone' and no 'rod'.

This means that they can see lots of colours — including those within the ultraviolet spectrum, like goldfish and parrots — but, at the same time, little contrast.

Able to operate independently of each other, their eyes have upper and lower lids that are joined together and can pivot in such a way that gives them nearly a complete 360° field of vision.

Tarantulas

Despite having eight of them, spider eyes are typically rather feeble.

Given this, the creepy-crawling are more reliant on their hairy legs, which allow them to feel their way around their world.

However, experts have recently found that their eyes contain colour-sensing proteins called opsins, which they think might be used to help them find mates.