Ophthalmology The critical angle refers to the angle of incidence in the denser medium, corresponding to which angle of refraction in the rarer medium is: A Less than 90deg B 90deg C More than 90deg D Equal to angle of incidence 💡 Explanation The critical angle refers to the angle of incidence in the denser medium, corresponding to which angle of refraction in the rarer medium is: ✓ Correct Answer: B. 90deg