We all have a strong survival instinct, one that kicks in the moment that we sense danger. For some of us, our 'fight or flight' mode can be a little too sensitive to perceived threats, and we end up scaring the hell out of ourselves for no particular reason.

But hey, better safe than sorry, am I right?

This list, compiled as a part 2 to this one by Bored Panda, is a series of times when people's hearts skipped several beats because of optical illusions, coincidences or just simple misunderstandings. From ghostly apparitions that turned out to be the delivery guy, to a seemingly sawn-in-half dog, you're sure to sympathize with the people who took these terrifying pics!

Scroll down below to check them out for yourself, and let us know what you think in the comments!

#1

This Freaked Me Out. Turns Out It's A Sunset Reflection

This Freaked Me Out. Turns Out It's A Sunset Reflection

PeteLX Report

Optical illusions challenge our sense of reality; they make us realize that what we see is simply our brains' best interpretation of the visual cues our eyes provide. Our brains have adapted not to see what is actually there, but what we deem as useful to see.

Optical illusions occur when a visual scene unfolds that is different from what our brain has decided is the norm, and it will respond in odd and often confusing ways until finally arriving at a conclusion.

#2

Had To Look Twice

Had To Look Twice

esquonk Report

According to Exploring optical illusions, there are 3 main types of optical illusion:

Literal illusions create images that are different from the objects that make them, like most of the entries on this list. For example, if 3 birds are flying, 2 above one, it can form the illusion of a smiling face.

Physiological illusions, such as afterimages following bright lights or adapting stimuli of excessively longer alternating patterns (contingent perceptual aftereffect), are presumed to be the effects on the eyes or brain of excessive stimulation of a specific type - brightness, tilt, color, movement, etc. The theory is that stimuli have individual dedicated neural paths in the early stages of visual processing, and that repetitive stimulation of only one or a few channels causes a physiological imbalance that alters perception. 

#3

Wife Left The Gloves To Dry, I Almost Had A Heart Attack

Wife Left The Gloves To Dry, I Almost Had A Heart Attack

RoninGR Report

#4

So Last Night I Was Positive There Was A Ghost Baby In The Bed With My Son

So Last Night I Was Positive There Was A Ghost Baby In The Bed With My Son

I was so freaked out, I barely slept. I even tried creeping in there with a flashlight while my son was sleeping. Well, this morning I go to investigate a bit further. It turns out my husband just forgot to put the mattress protector on when he changed the sheets. I could kill him.

Maritza Elizabeth Report

#5

Cat Gave Me A Scare This Morning. It's Paprika

Cat Gave Me A Scare This Morning. It's Paprika

bessiboom Report

Cognitive illusions are assumed to arise by interaction with assumptions about the world, leading to "unconscious inferences", an idea first suggested in the 19th century by Hermann Helmholtz. Cognitive illusions are commonly divided into ambiguous illusions, distorting illusions, paradox illusions, or fiction illusions.

1. Ambiguous illusions are pictures or objects that elicit a perceptual 'switch' between the alternative interpretations. The Necker cube is a well known example; another instance is the Rubin vase.

2. Distorting illusions are characterized by distortions of size, length, or curvature. A striking example is the Café wall illusion. Another example is the famous Müller-Lyer illusion. 

3. Paradox illusions are generated by objects that are paradoxical or impossible, such as the Penrose triangle or impossible staircases seen, for example, in M. C. Escher's Ascending and Descending and Waterfall. The triangle is an illusion dependent on a cognitive misunderstanding that adjacent edges must join. 

4. Fictional illusions are defined as the perception of objects that are genuinely not there to all but a single observer, such as those induced by schizophrenia or a hallucinogen. These are more properly called hallucinations. 

#6

Whoever Did This Gave Me A Heart Attack

Whoever Did This Gave Me A Heart Attack

JamesPKP Report

#7

My Dog Is Trying To Scare The Hell Out Of Me

My Dog Is Trying To Scare The Hell Out Of Me

erethenn Report

#8

Housemate Was Drying His Fishing Waders. Almost Had To Add The Pants I Was Wearing To The Laundry Pile I Was Carrying After I Opened The Door

Housemate Was Drying His Fishing Waders. Almost Had To Add The Pants I Was Wearing To The Laundry Pile I Was Carrying After I Opened The Door

jabrah15 Report

#9

The Snail In Our Office Fish Tank Freaked Me Out Today

The Snail In Our Office Fish Tank Freaked Me Out Today

Tyranitard Report

#10

Gives Me A Heart Attack Every Time, But He Loves To Sleep Like That!

Gives Me A Heart Attack Every Time, But He Loves To Sleep Like That!

morisaboo Report

#11

Scared The Hell Out Of Me When He Moved

Scared The Hell Out Of Me When He Moved

Nundee Report

#12

Emergency Light In The Hallway Scared The Hell Out Of Me Earlier. Meet The New Source Of My Nightmares

Emergency Light In The Hallway Scared The Hell Out Of Me Earlier. Meet The New Source Of My Nightmares

Tezariah Report

#13

Son Woke Us Up Around 3 AM To Tell Us Some Guy Was On Our Porch With A Stick

Son Woke Us Up Around 3 AM To Tell Us Some Guy Was On Our Porch With A Stick

After almost dying of a heart attack, we realized it was the paper delivery guy. With a branch. Trying to retrieve a mis-thrown paper from our roof while looking [friggin] terrifying.

thebeesremain Report

#14

My Grandma Taking A Nap. Scared The Hell Out Of Me At First

My Grandma Taking A Nap. Scared The Hell Out Of Me At First

joeltrane Report

#15

That Spooked The Hell Out Of Me

That Spooked The Hell Out Of Me

frex4 Report

#16

My Aunt Got Her Dog Groomed. The Groomer Only Has Half Of His Right Arm. It Looks Like He's Elbow Deep Into The Dog, And It Freaked Me Out When I First Saw The Picture

My Aunt Got Her Dog Groomed. The Groomer Only Has Half Of His Right Arm. It Looks Like He's Elbow Deep Into The Dog, And It Freaked Me Out When I First Saw The Picture

BaByJeZuZ012 Report

#17

These Bacon Slices Look Like An Evil Clown...

These Bacon Slices Look Like An Evil Clown...

jtronicustard Report

#18

My Cousin Woke Up In The Middle Of The Night, Randomly Looked At The Baby Monitor And Saw This. She Said It Scared The Hell Out Of Her

My Cousin Woke Up In The Middle Of The Night, Randomly Looked At The Baby Monitor And Saw This. She Said It Scared The Hell Out Of Her

jcmcna0733 Report

#19

I Bought My Wife (Who's A Professional Photographer) A Thermos In The Shape Of A Camera Lens. It Always Gives Me A Mini Heart Attack When I See It Like This

I Bought My Wife (Who's A Professional Photographer) A Thermos In The Shape Of A Camera Lens. It Always Gives Me A Mini Heart Attack When I See It Like This

Tryenamy Report

#20

I Didn’t Realize My Wife Left The Kids’ Presents In The Car Until I Checked The Rear View Mirror

I Didn’t Realize My Wife Left The Kids’ Presents In The Car Until I Checked The Rear View Mirror

Apatharas Report

#21

When You Walk In Your Room And Have A Mild Heart Attack

When You Walk In Your Room And Have A Mild Heart Attack

pooptime1 Report

#22

This Ultrasound Photo Scared My Husband

This Ultrasound Photo Scared My Husband

squidills Report

#23

Someone Spilled Their Smoothie In Class, And Now It Looks Like A Crime Scene

Someone Spilled Their Smoothie In Class, And Now It Looks Like A Crime Scene

Danielmg Report

See Also on Bored Panda
#24

I Put My Son In A Halloween Onesie Without Thinking Much About It And Gave Myself A Heart Attack At 2AM

I Put My Son In A Halloween Onesie Without Thinking Much About It And Gave Myself A Heart Attack At 2AM

LadyJane17 Report

#25

Ancient Whale Bone Over Top Of What Used To Be A Well

Ancient Whale Bone Over Top Of What Used To Be A Well

jahaight Report

#26

My Wife Had A Mini Heart Attack As We Drove Past This House. Nobody Lives There

My Wife Had A Mini Heart Attack As We Drove Past This House. Nobody Lives There

Its_Obvi_PShopped Report

#27

I Had A Mini Heart Attack When I Saw This. Spotted In NYC

I Had A Mini Heart Attack When I Saw This. Spotted In NYC

bmagnusson Report

#28

Sister Just Freaked Out, She Thought Someone Was In Her Flat. It Was Just Some Clothes Hanging Up In Front Of The Window

Sister Just Freaked Out, She Thought Someone Was In Her Flat. It Was Just Some Clothes Hanging Up In Front Of The Window

AndyWyant Report

#29

Scared The Hell Out Of Myself

Scared The Hell Out Of Myself

littlefoot2080 Report

#30

Nearly Gave Me A Heart Attack Upon First Glance

Nearly Gave Me A Heart Attack Upon First Glance

SJT29 Report

Note: this post originally had 64 images. It’s been shortened to the top 30 images based on user votes.