diff --git a/src/ray.rs b/src/ray.rs
index b10d480..cf60b28 100644
--- a/src/ray.rs
+++ b/src/ray.rs
@@ -1,18 +1,17 @@
-use crate::EPSILON;
+use crate::{EPSILON, EPSILON_VECTOR};
 
-use nalgebra::{Matrix4, Point3, Vector3};
+use nalgebra::{Matrix4, Point3, Unit, Vector3};
 
 pub struct Ray {
     pub a: Point3<f32>,
-    pub b: Vector3<f32>,
+    pub b: Unit<Vector3<f32>>,
 }
 
 impl Ray {
-    pub fn new(a: Point3<f32>, b: Vector3<f32>) -> Ray {
-        let b = b.normalize();
+    pub fn new(a: Point3<f32>, b: Unit<Vector3<f32>>) -> Ray {
         Ray { a, b }
     }
     pub fn at_t(&self, t: f32) -> Point3<f32> {
-        self.a + self.b * t
+        self.a + self.b.as_ref() * (t + EPSILON)
     }
 }