diff --git a/doc/examples/plot_blob.py b/doc/examples/plot_blob.py
index 53ac95d4..358b57c4 100644
--- a/doc/examples/plot_blob.py
+++ b/doc/examples/plot_blob.py
@@ -45,7 +45,7 @@ image = data.hubble_deep_field()[0:500, 0:500]
 image_gray = rgb2gray(image)
 
 blobs_log = blob_log(image_gray, max_sigma=30, num_sigma=10, threshold=.1)
-# Compute areas in the 2nd column.
+# Compute radii in the 3rd column.
 blobs_log[:, 2] = blobs_log[:, 2] * sqrt(2)
 
 blobs_dog = blob_dog(image_gray, max_sigma=30, threshold=.1)