diff --git a/docs/en/OPTIONS.txt b/docs/en/OPTIONS.txt
index 1e5af1cd4..f3682818b 100644
--- a/docs/en/OPTIONS.txt
+++ b/docs/en/OPTIONS.txt
@@ -6,7 +6,7 @@ Options Documentation
         Copyright (c) 2002-2021 by various contributors; see AUTHORS.txt
                             http://www.tuxpaint.org/
 
-                               December 27, 2020
+                                January 18, 2021
 
      ----------------------------------------------------------------------
 
@@ -116,6 +116,17 @@ Windows Users
              screen's current resolution (overriding any "windowsize"
              option), as set by the operating system.
 
+     buttonsize=SIZE
+
+             Set the pixel size of buttons in Tux Paint's user interface
+             (overriding the default of "48"). Useful when using very
+             high-density displays or coarse input devices, such as eye gaze
+             trackers.
+
+             The SIZE value should be presented in pixels, and can be
+             anything between 24 and 192, inclusive. Most buttons are square,
+             and this will affect their width and height.
+
      allowscreensaver=yes
 
              By default, Tux Paint prevents your system's screensaver from
diff --git a/docs/en/html/OPTIONS.html b/docs/en/html/OPTIONS.html
index b97b766b3..7ad83b262 100644
--- a/docs/en/html/OPTIONS.html
+++ b/docs/en/html/OPTIONS.html
@@ -32,7 +32,7 @@
       </p>
 
       <p>
-        December 27, 2020
+        January 18, 2021
       </p>
     </center>
 
@@ -261,6 +261,26 @@
           </p>
         </dd>
 
+        <dt>
+          <code><b>buttonsize=<i>SIZE</i></b></code>
+        </dt>
+
+        <dd>
+          <p>
+            Set the pixel size of buttons in <i>Tux&nbsp;Paint's</i>
+            user interface (overriding the default of "48").
+            Useful when using very high-density displays or coarse input
+            devices, such as eye gaze trackers.
+          </p>
+
+          <p>
+            The <i>SIZE</i> value should be presented in pixels,
+            and can be anything between 24 and 192, inclusive.
+            Most buttons are square, and this will affect their
+            width and height.
+          </p>
+        </dd>
+
         <dt>
           <code><b>allowscreensaver=yes</b></code>
         </dt>