3D Optical Illusions have always fascinated me. It never occurred to me that we could create 3D Crochet Blanket Patterns that could replicate the illusions!
I have searched online to find you some great free 3D Crochet Blanket Pattern options. I do not have permission to share photos for many of these but I definitely recommend you pop by and see the designs by Jellina Verhoeff. She is from the Netherlands and her posts are written in Dutch first and then followed by the English translation.
If you would like to try other Optical Illusion Crochet projects there are some available for purchase online. Here are a couple links to get you started:
Free 3D Crochet Blanket Patterns
You may also enjoy these great free patterns!
Illusion Infusion Blanket is available from Yarnspirations. This pretty blanket uses the block illusion. You will need Bulky Weight Yarn  and a 6.5 mm (K) hook to make your blanket. The afghan size is 50 inches X 60 inches.Read More
The Tumbling Blocks Throw from Yarnspirations is crocheted Medium Weight Yarn  and a 6 mm (J) hook. The afghan measures 44 inches X 54 inches.Read More
The Wacky Blocks Blanket was designed by Jellina at Jellina Creations. This modern and stylish project looks like the squares are moving (at least to my eyes!) You will need Medium Weight Yarn  and a 5 mm (H) hook.Read More
The Brain Teaser Blanket was designed by Jellina at Jellina Creations. I really love how this finished project, with it's brilliant rainbow of colored blocks looks. Each block literally looks like it is 3 dimensional. You will need Fingering Weight Yarn  and a 3 mm hook.Read More
The Bernice Blanket is one of my favorite designs by Jellina Verhoeff (so far). I feel like I am falling into the center of this blanket. She has created such depth to this with the colors she used. You will need Fingering Weight Yarn  and a 5 mm (H) hook.Read More
Neil's Temperature Blanket by Kaye Adolphson is a unique way to make an illusion blanket. The design is created by using half granny hexagons in 2 color pallets. The pattern is in UK Crochet Terms.Read More
The Pyramid Afghan by Bernhard Ulmann Co. is crocheted with Medium Weight yarn and a 3.5 mm (E) hook. The finished project measures 48 inches X 72 inches.Read More
The Tumbling Blocks blanket by Kat Li is created using Y-Shaped Tumbling Blocks. You will need Medium Weight Yarn and a 5.5 mm (I) hook.Read More
The Cubine Blanket designed by Magdalene Lee is based on the art of Zentangle. Her project is crocheted with DK Weight Yarn  with a 4 mm (G) hook. The finished size is 40 inches X 40 inches.Read More
The Blazing Diamonds Reversible Afghan by Hazel Furst is crocheted with Medium Weight Yarn  and a 5 mm (H) hook. The finished afghan measures 50 inches X 65 inches.Read More
Baby Blocks was crocheted with Medium Weight Yarn  and a 5 mm (H) hook. The finished blanket measures 42 inches X 44 inches in size. The blanket is created in a join as you go way and each motif measures 4 inches by 6.5 inches.Read More
The Double A Design Blanket was a combined design effort between Atty's and Annelies Baes. Annelies used DK Weight Yarn  and a 4 mm (G) hook to make her shadowed squares. She used a 4.5 mm hook to join the squares into the design.Read More
The 3D Diamond Throw available from Spotlight Australia is a fun twist on the regular diamond throws available. The diamonds are created using 15 X 10 cm granny squares. You will need DK Weight Yarn  and a 6 mm (J) hook.Read More
The Isometric designed by Solveig Grimstad creates a fantastic optical illusion blanket. Her post is filled with photos and diagrams to help you make your own afghan. She crocheted her blanket with DROPS Karisma and a 4.5 mm hook.Read More
The Optical Illusion Afghan designed by Lois Olson is crocheted with Medium Weight Yarn  and a 4 mm (G) hook. This is a very unique afghan and the first one using the pinwheel illusion that I have seen online.Read More
I really like how Jellina created these blocks with 3 diamonds in different colors sewn together. It creates a stunning visual illusion with the colors she chose. There is a lot of depth to them and it is the first 3D Blanket I have seen that makes me see upside down cubes and upright cubes.Read More