diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,21 +1,27 @@
-0.1
+0.5.0.0
 ---
-* Initial release (moved from Plot-ho-matic repo)
+* Use lenses intead of hand-rolled Getter/Setters
+* add describeField function
+* add sameFieldType function
 
-0.2 (broken, do not use)
+0.4.1
 ---
-* Add setters
-* Make getters support more types than Double
+* add version of flatten which returns name as [String]
 
+0.4
+---
+* Revive convenience show functions
+* Ints and Bools are no longer shown as floats
+
 0.3
 ---
 * Fix setters
 
-0.4
+0.2 (broken, do not use)
 ---
-* Revive convenience show functions
-* Ints and Bools are no longer shown as floats
+* Add setters
+* Make getters support more types than Double
 
-0.4.1
+0.1
 ---
-* add version of flatten which returns name as [String]
+* Initial release (moved from Plot-ho-matic repo)
diff --git a/generic-accessors.cabal b/generic-accessors.cabal
--- a/generic-accessors.cabal
+++ b/generic-accessors.cabal
@@ -1,5 +1,5 @@
 name:                generic-accessors
-version:             0.4.2.0
+version:             0.5.0.0
 synopsis:            stringly-named getters for generic data
 license:             BSD3
 license-file:        LICENSE
@@ -15,9 +15,13 @@
   CHANGELOG.md
   README.md
 description: {
-Get a Tree or list of (String, a -> Double) pairs for use in plotting and data inspection
+Get a Tree or list of (String, Lens a X) pairs for use in plotting and data inspection
 }
 
+source-repository head
+  type:     git
+  location: git://github.com/ghorn/generic-accessors.git
+
 library
   hs-source-dirs:    src
   default-language:  Haskell2010
@@ -25,6 +29,7 @@
   build-depends:     base >= 4.6.0.0 && < 5
                      , linear
                      , spatial-math >= 0.2.0
+                     , lens
 
   ghc-options:      -O2 -Wall
   ghc-prof-options: -O2 -Wall -prof -fprof-auto -fprof-cafs -rtsopts
diff --git a/src/Accessors.hs b/src/Accessors.hs
--- a/src/Accessors.hs
+++ b/src/Accessors.hs
@@ -1,17 +1,18 @@
 {-# OPTIONS_GHC -Wall #-}
---{-# OPTIONS_GHC -ddump-deriv #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE DefaultSignatures #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 
 module Accessors
        ( Lookup(..)
        , AccessorTree(..)
-       , Setter(..)
-       , Getter(..)
+       , Field(..)
        , accessors
+       , describeField
+       , sameFieldType
        , flatten
        , flatten'
        , showTree
@@ -20,6 +21,7 @@
 
 import GHC.Generics
 
+import Control.Lens ( Lens', (^.) )
 import Data.List ( intercalate )
 import qualified Linear
 import GHC.Word
@@ -30,7 +32,7 @@
 import SpatialMathT ( V3T(..), Rot(..) )
 
 showAccTree :: String -> AccessorTree a -> [String]
-showAccTree spaces (ATGetter _) = [spaces ++ "ATGetter {}"]
+showAccTree spaces (Field _) = [spaces ++ "Field {}"]
 showAccTree spaces (Data name trees) =
   (spaces ++ "Data " ++ show name) :
   concatMap (showChild (spaces ++ "    ")) trees
@@ -43,41 +45,51 @@
   show = unlines . showAccTree ""
 
 data AccessorTree a = Data (String,String) [(String, AccessorTree a)]
-                    | ATGetter (Getter a, Setter a)
+                    | Field (Field a)
 
-data Getter a =
-  GetBool (a -> Bool)
-  | GetDouble (a -> Double)
-  | GetFloat (a -> Float)
-  | GetInt (a -> Int)
-  | GetString (a -> String)
-  | GetSorry -- ^ not yet implemented
+data Field a =
+  FieldBool (Lens' a Bool)
+  | FieldDouble (Lens' a Double)
+  | FieldFloat (Lens' a Float)
+  | FieldInt (Lens' a Int)
+  | FieldString (Lens' a String)
+  | FieldSorry -- ^ a field which is not yet supported
 
-data Setter a =
-  SetBool (Bool -> a -> a)
-  | SetDouble (Double -> a -> a)
-  | SetFloat (Float -> a -> a)
-  | SetInt (Int -> a -> a)
-  | SetString (String -> a -> a)
-  | SetSorry -- ^ not yet implemented
+-- | Return the type of field, such as "Bool", "Double", "String", etc.
+describeField :: Field a -> String
+describeField (FieldBool _) = "Bool"
+describeField (FieldDouble _) = "Double"
+describeField (FieldFloat _) = "Float"
+describeField (FieldInt _) = "Int"
+describeField (FieldString _) = "String"
+describeField FieldSorry = "Sorry"
 
-accessors :: Lookup a => a -> AccessorTree a
-accessors x = toAccessorTree x id (\new _ -> new)
---accessors = flip (flip toAccessorTree id) id
+-- | Returns True if the __type__ of fields is the same.
+sameFieldType :: Field a -> Field b -> Bool
+sameFieldType (FieldBool _) (FieldBool _) = True
+sameFieldType (FieldDouble _) (FieldDouble _) = True
+sameFieldType (FieldFloat _) (FieldFloat _) = True
+sameFieldType (FieldInt _) (FieldInt _) = True
+sameFieldType (FieldString _) (FieldString _) = True
+sameFieldType FieldSorry FieldSorry = True
+sameFieldType _ _ = False
 
+accessors :: Lookup a => AccessorTree a
+accessors = toAccessorTree id
+
 showMsgs :: [String] -> String
 showMsgs = intercalate "."
 
-flatten :: AccessorTree a -> [(String, Getter a, Setter a)]
+flatten :: AccessorTree a -> [(String, Field a)]
 flatten = map f . flatten'
   where
-    f (x,y,z) = (showMsgs x, y, z)
+    f (x,y) = (showMsgs x, y)
 
-flatten' :: AccessorTree a -> [([String], Getter a, Setter a)]
+flatten' :: AccessorTree a -> [([String], Field a)]
 flatten' = flattenChain []
   where
-    flattenChain :: [String] -> AccessorTree a -> [([String], Getter a, Setter a)]
-    flattenChain msgs (ATGetter (get, set)) = [(reverse msgs, get, set)]
+    flattenChain :: [String] -> AccessorTree a -> [([String], Field a)]
+    flattenChain msgs (Field lens) = [(reverse msgs, lens)]
     flattenChain msgs (Data (_,_) trees) = concatMap f trees
       where
         f (name,tree) = flattenChain (name:msgs) tree
@@ -85,235 +97,218 @@
 -- | Things which you can make a tree of labeled getters for.
 -- You should derive this using GHC.Generics.
 class Lookup a where
-  toAccessorTree :: a -> (b -> a) -> (a -> b -> b) -> AccessorTree b
+  toAccessorTree :: Lens' b a -> AccessorTree b
 
-  default toAccessorTree :: (Generic a, GLookup (Rep a)) => a -> (b -> a) -> (a -> b -> b) -> AccessorTree b
-  toAccessorTree x get set = gtoAccessorTree (from x) (from . get) (set . to)
+  default toAccessorTree :: (Generic a, GLookup (Rep a))
+                            => Lens' b a -> AccessorTree b
+  toAccessorTree lens0 = gtoAccessorTree (lens0 . repLens)
+    where
+      repLens :: Lens' a (Rep a p)
+      repLens f y = fmap to (f (from y))
 
 class GLookup f where
-  gtoAccessorTree :: f a -> (b -> f a) -> (f a -> b -> b) -> AccessorTree b
+  gtoAccessorTree :: Lens' b (f a) -> AccessorTree b
 
 class GLookupS f where
-  gtoAccessorTreeS :: f a -> (b -> f a) -> (f a -> b -> b) -> [(String, AccessorTree b)]
+  gtoAccessorTreeS :: Lens' b (f a)
+                      -> [(String, AccessorTree b)]
 
+instance Lookup f => GLookup (Rec0 f) where
+  gtoAccessorTree lens0 = toAccessorTree (lens0 . rec0Lens)
+    where
+      rec0Lens :: Lens' (Rec0 f a) f
+      rec0Lens f y = fmap K1 (f (unK1 y))
+
+instance (Selector s, GLookup a) => GLookupS (S1 s a) where
+  gtoAccessorTreeS lens0 = [(selname, gtoAccessorTree (lens0 . m1Lens))]
+    where
+      m1Lens :: Lens' (S1 s f p) (f p)
+      m1Lens f y = fmap M1 (f (unM1 y))
+
+      selname = case selName selError of
+        "" -> "()"
+        y -> y
+
+      selError :: S1 s a p
+      selError = error $ "generic-accessors: selName should never access data"
+
+
+instance GLookupS U1 where
+  gtoAccessorTreeS _ = []
+
+instance (GLookupS f, GLookupS g) => GLookupS (f :*: g) where
+  gtoAccessorTreeS lens0 = tf ++ tg
+    where
+      tf = gtoAccessorTreeS (lens0 . leftLens)
+      tg = gtoAccessorTreeS (lens0 . rightLens)
+
+      leftLens ::  Lens' ((f :*: g) a) (f a)
+      leftLens  f (x :*: y) = fmap (\x' -> x' :*: y ) (f x)
+      rightLens :: Lens' ((f :*: g) a) (g a)
+      rightLens f (x :*: y) = fmap (\y' -> x  :*: y') (f y)
+
+instance (Datatype d, Constructor c, GLookupS a)
+         => GLookup (D1 d (C1 c a)) where
+  gtoAccessorTree lens0 = Data (datatypeName datatypeError, conName conError) con
+    where
+      conError :: C1 c a p
+      conError = error $ "generic-accessors: conName should never access data"
+
+      datatypeError :: D1 d (C1 c a) p
+      datatypeError = error $ "generic-accessors: datatypeName should never access data"
+
+      con = gtoAccessorTreeS (lens0 . m1m1Lens)
+
+      m1m1Lens :: Lens' (D1 d (C1 c f) p) (f p)
+      m1m1Lens f y = fmap (M1 . M1) (f (unM1 (unM1 y)))
+
 -- some instance from linear
 instance Lookup a => Lookup (Linear.V0 a) where
-  toAccessorTree _ _ _ =
+  toAccessorTree _ =
     Data ("V0", "V0") []
 instance Lookup a => Lookup (Linear.V1 a) where
-  toAccessorTree xyz get set =
-    Data ("V1", "V1") [ ("x", toAccessorTree (getX xyz) (getX . get) setX)
+  toAccessorTree lens0 =
+    Data ("V1", "V1") [ ("x", toAccessorTree (lens0 . Linear._x))
                       ]
-    where
-      getX (Linear.V1 x) = x
-      setX x new = set (Linear.V1 x) new
+
 instance Lookup a => Lookup (Linear.V2 a) where
-  toAccessorTree (Linear.V2 x0 y0) get set =
-    Data ("V2", "V2") [ ("x", toAccessorTree x0 (getX . get) setX)
-                      , ("y", toAccessorTree y0 (getY . get) setY)
+  toAccessorTree lens0 =
+    Data ("V2", "V2") [ ("x", toAccessorTree (lens0 . Linear._x))
+                      , ("y", toAccessorTree (lens0 . Linear._y))
                       ]
-    where
-      getX (Linear.V2 x _) = x
-      getY (Linear.V2 _ y) = y
 
-      setX x new = set (Linear.V2 x (getY (get new))) new
-      setY y new = set (Linear.V2 (getX (get new)) y) new
-
 instance Lookup a => Lookup (Linear.V3 a) where
-  toAccessorTree (Linear.V3 x0 y0 z0) get set =
-    Data ("V3", "V3") [ ("x", toAccessorTree x0 (getX . get) setX)
-                      , ("y", toAccessorTree y0 (getY . get) setY)
-                      , ("z", toAccessorTree z0 (getZ . get) setZ)
+  toAccessorTree lens0 =
+    Data ("V3", "V3") [ ("x", toAccessorTree (lens0 . Linear._x))
+                      , ("y", toAccessorTree (lens0 . Linear._y))
+                      , ("z", toAccessorTree (lens0 . Linear._z))
                       ]
-    where
-      getX (Linear.V3 x _ _) = x
-      getY (Linear.V3 _ y _) = y
-      getZ (Linear.V3 _ _ z) = z
-      setX x new = set (Linear.V3 x y z) new
-        where
-          Linear.V3 _ y z = get new
-      setY y new = set (Linear.V3 x y z) new
-        where
-          Linear.V3 x _ z = get new
-      setZ z new = set (Linear.V3 x y z) new
-        where
-          Linear.V3 x y _ = get new
 instance Lookup a => Lookup (Linear.V4 a) where
-  toAccessorTree (Linear.V4 x0 y0 z0 w0) get set =
-    Data ("V4", "V4") [ ("x", toAccessorTree x0 (getX . get) setX)
-                      , ("y", toAccessorTree y0 (getY . get) setY)
-                      , ("z", toAccessorTree z0 (getZ . get) setZ)
-                      , ("w", toAccessorTree w0 (getW . get) setW)
+  toAccessorTree lens0 =
+    Data ("V4", "V4") [ ("x", toAccessorTree (lens0 . Linear._x))
+                      , ("y", toAccessorTree (lens0 . Linear._y))
+                      , ("z", toAccessorTree (lens0 . Linear._z))
+                      , ("w", toAccessorTree (lens0 . Linear._w))
                       ]
-    where
-      getX (Linear.V4 x _ _ _) = x
-      getY (Linear.V4 _ y _ _) = y
-      getZ (Linear.V4 _ _ z _) = z
-      getW (Linear.V4 _ _ _ w) = w
-      setX x new = set (Linear.V4 x y z w) new
-        where
-          Linear.V4 _ y z w = get new
-      setY y new = set (Linear.V4 x y z w) new
-        where
-          Linear.V4 x _ z w = get new
-      setZ z new = set (Linear.V4 x y z w) new
-        where
-          Linear.V4 x y _ w = get new
-      setW w new = set (Linear.V4 x y z w) new
-        where
-          Linear.V4 x y z _ = get new
 instance Lookup a => Lookup (Linear.Quaternion a) where
-  toAccessorTree (Linear.Quaternion q0 (Linear.V3 x0 y0 z0)) get set =
+  toAccessorTree lens0 =
     Data ("Quaternion", "Quaternion")
-    [ ("q0", toAccessorTree q0 (getQ0 . get) setQ0)
-    , ("q1", toAccessorTree x0 (getQ1 . get) setQ1)
-    , ("q2", toAccessorTree y0 (getQ2 . get) setQ2)
-    , ("q3", toAccessorTree z0 (getQ3 . get) setQ3)
+    [ ("q0", toAccessorTree (lens0 . Linear._e))
+    , ("q1", toAccessorTree (lens0 . Linear._i))
+    , ("q2", toAccessorTree (lens0 . Linear._j))
+    , ("q3", toAccessorTree (lens0 . Linear._k))
     ]
-    where
-      getQ0 (Linear.Quaternion q _) = q
-      getQ1 (Linear.Quaternion _ (Linear.V3 x _ _)) = x
-      getQ2 (Linear.Quaternion _ (Linear.V3 _ y _)) = y
-      getQ3 (Linear.Quaternion _ (Linear.V3 _ _ z)) = z
 
-      setQ0 q new = set (Linear.Quaternion q (Linear.V3 x y z)) new
-        where
-          Linear.Quaternion _ (Linear.V3 x y z) = get new
-      setQ1 x new = set (Linear.Quaternion q (Linear.V3 x y z)) new
-        where
-          Linear.Quaternion q (Linear.V3 _ y z) = get new
-      setQ2 y new = set (Linear.Quaternion q (Linear.V3 x y z)) new
-        where
-          Linear.Quaternion q (Linear.V3 x _ z) = get new
-      setQ3 z new = set (Linear.Quaternion q (Linear.V3 x y z)) new
-        where
-          Linear.Quaternion q (Linear.V3 x y _) = get new
-
-
-instance Lookup f => GLookup (Rec0 f) where
-  gtoAccessorTree x get set = toAccessorTree (unK1 x) (unK1 . get) (set . K1)
-
-instance (Selector s, GLookup a) => GLookupS (S1 s a) where
-  gtoAccessorTreeS x get set = [(selname, gtoAccessorTree (unM1 x) (unM1 . get) (set . M1))]
-    where
-      selname = case selName x of
-        [] -> "()"
-        y -> y
-
-instance GLookupS U1 where
-  gtoAccessorTreeS _ _ _ = []
-
-instance (GLookupS f, GLookupS g) => GLookupS (f :*: g) where
-  gtoAccessorTreeS (x0 :*: y0) get set = tf ++ tg
-    where
-      tf = gtoAccessorTreeS x0 (getLeft  . get) setLeft
-      tg = gtoAccessorTreeS y0 (getRight . get) setRight
-
-      getLeft  (x :*: _) = x
-      getRight (_ :*: y) = y
-
-      setLeft  x new = set (x :*: getRight (get new)) new
-      setRight y new = set (getLeft (get new) :*: y) new
-
-instance (Datatype d, Constructor c, GLookupS a) => GLookup (D1 d (C1 c a)) where
-  gtoAccessorTree d@(M1 c) get set = Data (datatypeName d, conName c) con
-    where
-      con = gtoAccessorTreeS (unM1 c) (unM1 . unM1 . get) (set . M1 . M1)
-
 -- basic types
 instance Lookup () where -- hack to get dummy tree
-  toAccessorTree _ _ _ = ATGetter (GetSorry, SetSorry)
+  toAccessorTree _ = Field FieldSorry
 instance Lookup Int where
-  toAccessorTree _ get set = ATGetter (GetInt get, SetInt set)
+  toAccessorTree lens = Field (FieldInt lens)
 instance Lookup Float where
-  toAccessorTree _ get set = ATGetter (GetFloat get, SetFloat set)
+  toAccessorTree lens = Field (FieldFloat lens)
 instance Lookup Double where
-  toAccessorTree _ get set = ATGetter (GetDouble get, SetDouble set)
+  toAccessorTree lens = Field (FieldDouble lens)
 instance Lookup Bool where
-  toAccessorTree _ get set = ATGetter (GetBool get, SetBool set)
+  toAccessorTree lens = Field (FieldBool lens)
 instance Lookup String where
-  toAccessorTree _ get set = ATGetter (GetString get, SetString set)
+  toAccessorTree lens = Field (FieldString lens)
 
 -- Word types
 instance Lookup Word where
-  toAccessorTree _ get _ = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup Word8 where
-  toAccessorTree _ get _ = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup Word16 where
-  toAccessorTree _ get _ = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup Word32 where
-  toAccessorTree _ get _ = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup Word64 where
-  toAccessorTree _ get _ = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 
 -- Int types
 instance Lookup Int8 where
-  toAccessorTree _ get _ = ATGetter (GetInt (fromIntegral . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup Int16 where
-  toAccessorTree _ get _ = ATGetter (GetInt (fromIntegral . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup Int32 where
-  toAccessorTree _ get _ = ATGetter (GetInt (fromIntegral . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup Int64 where
-  toAccessorTree _ get _ = ATGetter (GetInt (fromIntegral . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 
--- todo(greg): some of these getters can fit in ints
 -- C types
+-- todo(greg): some of these have inappropriate fields
 instance Lookup CChar where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CSChar where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CUChar where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CShort where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CUShort where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CInt where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CUInt where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CLong where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CULong where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CPtrdiff where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CSize where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CWchar where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CSigAtomic where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CLLong where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CULLong where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CIntPtr where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CUIntPtr where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CIntMax where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CUIntMax where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . integralLens))
 instance Lookup CClock where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . clockLens))
+    where
+      clockLens f (CClock x) = fmap (CClock . fromIntegral) (f (fromIntegral x))
 instance Lookup CTime where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . timeLens))
+    where
+      timeLens f (CTime x) = fmap (CTime . fromIntegral) (f (fromIntegral x))
 instance Lookup CUSeconds where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . usecondsLens))
+    where
+      usecondsLens f (CUSeconds x) = fmap (CUSeconds . fromIntegral) (f (fromIntegral x))
 instance Lookup CSUSeconds where
-  toAccessorTree _ get _set = ATGetter (GetDouble (realToFrac . get), SetSorry)
+  toAccessorTree lens0 = Field (FieldInt (lens0 . susecondsLens))
+    where
+      susecondsLens f (CSUSeconds x) = fmap (CSUSeconds . fromIntegral) (f (fromIntegral x))
 instance Lookup CFloat where
-  toAccessorTree _ get set = ATGetter (GetFloat (realToFrac . get), SetFloat (set . realToFrac))
+  toAccessorTree lens0 = Field (FieldDouble (lens0 . realFracLens))
 instance Lookup CDouble where
-  toAccessorTree _ get set = ATGetter (GetDouble (realToFrac . get), SetDouble (set . realToFrac))
+  toAccessorTree lens0 = Field (FieldDouble (lens0 . realFracLens))
 
+{-# INLINE integralLens #-}
+integralLens :: Integral a => Lens' a Int
+integralLens f x = fmap fromIntegral (f (fromIntegral x))
+
+{-# INLINE realFracLens #-}
+realFracLens :: (Fractional a, Real a) => Lens' a Double
+realFracLens f x = fmap realToFrac (f (realToFrac x))
+
 -- other types
 instance Lookup a => Lookup (Rot f1 f2 a) where
-  toAccessorTree x get set = toAccessorTree (unR x) (unR . get) (set . Rot)
+  toAccessorTree lens0 = toAccessorTree (lens0 . (\f x -> fmap Rot (f (unR x))))
 instance Lookup a => Lookup (V3T f a) where
-  toAccessorTree x get set = toAccessorTree (unV x) (unV . get) (set . V3T)
+  toAccessorTree lens0 = toAccessorTree (lens0 . (\f x -> fmap V3T (f (unV x))))
 instance Lookup a => Lookup (Euler a)
 
 showAccTrees :: (Double -> String) -> a -> [(String, AccessorTree a)] -> String -> [String]
@@ -321,17 +316,17 @@
   where
     cs = zipWith (showRecordField show' x spaces) trees ("{ " : repeat ", ")
 
-showVal :: Getter a -> (Double -> String) -> a -> String
-showVal (GetBool get) _ x = show (get x)
-showVal (GetInt get) _ x = show (get x)
-showVal (GetDouble get) show' x = show' (get x)
-showVal (GetFloat get) show' x = show' (realToFrac (get x))
-showVal (GetString get) _ x = get x
-showVal GetSorry _ _ = ""
+showVal :: Field a -> (Double -> String) -> a -> String
+showVal (FieldBool lens) _ x = show (x ^. lens)
+showVal (FieldInt lens) _ x = show (x ^. lens)
+showVal (FieldDouble lens) show' x = show' (x ^. lens)
+showVal (FieldFloat lens) show' x = show' (realToFrac (x ^. lens))
+showVal (FieldString lens) _ x = x ^. lens
+showVal FieldSorry _ _ = ""
 
 showRecordField :: (Double -> String) -> a -> String -> (String, AccessorTree a) -> String -> [String]
-showRecordField show' x spaces (getterName, ATGetter (get, _)) prefix =
-  [spaces ++ prefix ++ getterName ++ " = " ++ showVal get show' x]
+showRecordField show' x spaces (getterName, (Field field)) prefix =
+  [spaces ++ prefix ++ getterName ++ " = " ++ showVal field show' x]
 showRecordField show' x spaces (getterName, Data (_,cons) trees) prefix =
   (spaces ++ prefixNameEq ++ cons) : showAccTrees show' x trees newSpaces
   where
@@ -346,7 +341,7 @@
 -- | Show a tree of values
 showTree :: AccessorTree a -> (Double -> String) -> a -> String
 showTree (Data (_,cons) trees) show' x = initUnlines $ cons : showAccTrees show' x trees ""
-showTree (ATGetter (get,_)) show' x = showVal get show' x
+showTree (Field field) show' x = showVal field show' x
 
 -- | Show a list of values
 -- .
@@ -354,14 +349,13 @@
 showFlat :: forall a . AccessorTree a -> Bool -> (Double -> String) -> a -> String
 showFlat at align show' x = initUnlines $ map f fl
   where
-    fst3 (z,_,_) = z
-    n = maximum (map (length . fst3) fl)
+    n = maximum (map (length . fst) fl)
 
-    f (name, get, _) = name ++ spaces ++ " = " ++ showVal get show' x
+    f (name, lens) = name ++ spaces ++ " = " ++ showVal lens show' x
       where
         spaces
           | align = replicate (n - length name) ' '
           | otherwise = ""
 
-    fl :: [(String, Getter a, Setter a)]
+    fl :: [(String, Field a)]
     fl = flatten at
diff --git a/tests/Tests.hs b/tests/Tests.hs
--- a/tests/Tests.hs
+++ b/tests/Tests.hs
@@ -55,7 +55,7 @@
 foo = MkFoo 2 (Xyz 6 7 8 9) True False yo (MkOne 17)
 
 yup :: AccessorTree Foo
-yup = accessors foo
+yup = accessors
 
 
 accessorTests :: Test