diff --git a/changelog b/changelog
--- a/changelog
+++ b/changelog
@@ -1,3 +1,7 @@
+0.0.6
+
+* Remove dependency on lens.
+
 0.0.5
 
 * Fix documentation.
diff --git a/radian.cabal b/radian.cabal
--- a/radian.cabal
+++ b/radian.cabal
@@ -1,5 +1,5 @@
 name:               radian
-version:            0.0.5
+version:            0.0.6
 license:            BSD3
 license-file:       LICENCE
 author:             Tony Morris <ʇǝu˙sıɹɹoɯʇ@ןןǝʞsɐɥ>
@@ -30,7 +30,7 @@
 
   build-depends:
                       base < 5 && >= 3
-                    , lens >= 4.0
+                    , profunctors >= 3.1.1
 
   ghc-options:
                     -Wall
@@ -61,6 +61,7 @@
                     , directory >= 1.1
                     , QuickCheck >= 2.0
                     , template-haskell >= 2.8
+                    , lens >= 4.0
 
   ghc-options:
                     -Wall
diff --git a/src/Data/Radian.hs b/src/Data/Radian.hs
--- a/src/Data/Radian.hs
+++ b/src/Data/Radian.hs
@@ -1,12 +1,13 @@
 {-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE RankNTypes #-}
 
 module Data.Radian(
   toRadians
 , fromRadians
 ) where
 
-import Control.Lens(Iso, iso, from)
+import Data.Functor(Functor(fmap))
+import Data.Profunctor(Profunctor(dimap))
 import Prelude(Num((*)), Fractional((/)), Floating, pi)
 
 -- $setup
@@ -39,9 +40,9 @@
   (Floating a, Floating b) =>
   Iso a b a b
 toRadians =
-  iso
-    (\a -> a / pi * 180)
-    (\a -> a / 180 * pi)   
+  dimap
+    to
+    (fmap fr)
 
 -- | An isomorphism between degrees and radians.
 --
@@ -60,4 +61,27 @@
   (Floating a, Floating b) =>
   Iso a b a b
 fromRadians =
-  from toRadians
+  dimap
+    fr
+    (fmap to)
+
+----
+
+to ::
+  Floating a =>
+  a
+  -> a
+to a =
+  a / pi * 180
+
+fr ::
+  Floating a =>
+  a
+  -> a
+fr a =
+  a / 180 * pi
+
+type Iso s t a b =
+  forall p f.
+  (Profunctor p, Functor f) =>
+  p a (f b) -> p s (f t)