refractive index of immersion oil verses water

[april]

Viewing a slide under a microscope, What would happen if water were used in place of immersion oil?
I know that immersion oil has a refractive index (N=1.52) which is the same as glass. I believe water has the same refractive index as air, so viewing under water on a microscope would be like having nothing on a slide, am I correct?

The refraction index for water is about 4/3. It is not the same as air (refraction index is very close to 1)