(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The cornea, a boundary between the air and the aqueous humor, has a 3.0cm focal length when acting alone.

What is its radius of curvature?

2. Relevant equations

n(1)/s + n(2)/s' = (n(2)-n(1))/R

where, n is the index of refraction (unitless), s' is the img dist (cm). and s is the obj. dist (cm). R is the radius (cm).

also, 1/s + 1/s' = 1/f

where, f is the focal length.

also, n(1) is air having a index of refraction of 1.00

and n(2) is the aqueous humor having a index of refraction of 1.34

3. The attempt at a solution

So, I assumed since only f was given as 3.0cm that 1/s' + 1/s could be 1/6.0cm + 1/6.0cm = 1/3.0cm. Then that would give 1.00/6.0cm + 1.34/6.0cm = (1.34-1.00)/R giving R to be 0.87cm but it says that is wrong. Any ideas??? Also, I thought there was a equation editor for this website? I can't seem to see it... Is it only for the premium members?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Radius of curvature of the cornea

**Physics Forums | Science Articles, Homework Help, Discussion**