Op Art was a movement in the sixties that played with people's minds: it made 2D lines feel 3 dimensional and still lines seem to vibrate or move in unexpected ways.
Line is the first element we will cover in our Elements of Art lessons. One idea for a project is to use the edge of a bulletin board border. (To my virtual students, I sent you each a piece of this in your last packet of supplies). Hold it vertical and trace the bumpy edge near the left hand side of of a vertical piece of paper. Then move the boarder template to the left and down just a tad and trace another line. Repeat the process until the entire paper is full. If you are using a chisaled marker, consider using the wide edge on the in stroke and the thin edge on the out stroke over visa versa. When you turn the finished drawing on its side it gives the illusion of bumps or waves.
For students with little to no vision, there's an option to use Wiki Sticks to create a few simple shapes. You may use a circle in the middle of the page, or squares poking in from edges or a combination of those ideas.
Hold your paper horizontally and draw vertical, parallel lines in the background (around the shapes). You can use a ruler if you like. Move the ruler a little to the left each time and make sure it stays parallel to the sides of the paper. If you would rather it be tactile lines, use puffy paint, liquid glue, glued, strips of paper, or Wiki Stix to create your lines.
Then rotate your paper 90 degrees or in an angle that aligns with the edge of one of your shapes, and create parallel lines going in that direction.
For a modification of this option, I have included paper with stripes of puffy paint. Cut the bottom 1/3 or 1/4 of the paper off. Cut it into simple shapes, like square or triangles. Glue it on the larger striped sheet being sure to change the direction of the stripes.
For my students with some vision, there's yet another option, Create a funnel shape, draw two lines coming in and down from either side of the paper. Start at the bottom of that funnel ad make a frown arch going up and off the top of the page. For the background make smiles lines going behind the funnel.
To create a funnel form a higher point of view, looking down into the top, make the lines curving up on the sides on top of the form. Verticle lines can come straight up and out of the top "smile" shaped line, and move out to the corners. (Lines on the right curve right and left lines curve left at the top of the page.
You may draw straight, parallel, horizontal lines in the background, for the illusion of flat space, or you can make frowny arched lines to make it look like the sides are curving towards you. I chose to make a flat space in the example below.
There are many ways to use lines to create optical illusions. Make spheres or cubes; fill the space. Play around and have some fun with it.