How to calculate the curvature of the eye

STEP 1 While staring straight ahead, measure the distance between the inner corner of the eye and the outer corner of the eye with a ruler.
STEP 2 Mark the straight line length of the eye measured with a ruler on the paper.
STEP 3 Cut a long strip of paper and place it over the eye. Mark the starting and ending points of the eye on the paper.
STEP 4 Attach a piece of paper with a curved length in an arch shape over the previously calculated horizontal length.
STEP 5 Measure the height of the arch accurately using a ruler.
STEP 6 Calculate the curvature by entering the width and height values ​​on a curvature calculation site.