1. At age 6 a person has a range of accommodation from f = 2.0 cm to f = 1.67 cm

Question

1. At age 6 a person has a range of accommodation from f = 2.0 cm to f = 1.67 cm for the lens of his eye. What is his closest focusing distance? Assume a lens-to-retina distance to be 2.0 cm. 2. At age 60 a person can accommodate the focal length of his eye's lens only over the range f = 2.0 cm to f = 1.92 cm. What is the distance at which she could focus clearly? Assume a lens-to-retina distance of 2.0 cm. (Show Work) 1. At age 6 a person has a range of accommodation from f = 2.0 cm to f = 1.67 cm for the lens of his eye. What is his closest focusing distance? Assume a lens-to-retina distance to be 2.0 cm. 2. At age 60 a person can accommodate the focal length of his eye's lens only over the range f = 2.0 cm to f = 1.92 cm. What is the distance at which she could focus clearly? Assume a lens-to-retina distance of 2.0 cm. (Show Work)

Explanation / Answer

1.1/F = 1/Obj + 1/Im,

So plugging in what we know, we have

1/1.67 = 1/Obj + 1/2,

since the lens to retina distance, Im, is 2 cm, and the lower focal length is F. Subtracting 1/2 from both sides yields

1/Obj = .0988,

and inverting then yields

Obj = 10.12 cm.

2.1/F = 1/Obj + 1/Im,

So plugging in what we know, we have

1/1.92 = 1/Obj + 1/2,

since the lens to retina distance, Im, is 2 cm, and the lower focal length is F. Subtracting 1/2 from both sides yields

1/Obj = .020833

and inverting then yields

Obj = 48cm.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.