1. Keanu is 47 years old, and the amplitude of accommodation in his left eye is about one standard deviation above average for his age. From now on, we concentrate exclusively on his left eye. When Keanu's eye is unaided by vision correction, he can focus on objects about 40 cm in front of it, but not closer. He has a Maximum Accommodation of 5 Diopters.

1.1. Show that Keanu's eye's sphere correction is about +2.5 D. Use this result in later problems even if you don't successfully compute it.

1.2. Is Keanu's eye hyperopic, emmetropic, or myopic?

1.3. If Keanu's eye has a minimum power of 57.5 D, what is its lens-retina distance d ?