Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What change can cataracts and diabetes mellitus cause in relation to myopia?

1. Increased lens curvature

2. Increased refractive index of the crystalline lens

3. Reduced lens flexibility

4. Thickening of the cornea

The correct answer is: Increased refractive index of the crystalline lens

Cataracts and diabetes mellitus can lead to an increased refractive index of the crystalline lens, which affects vision. In the case of cataracts, the lens becomes cloudy and its optical properties change, which can result in a higher refractive index. This change means that light entering the eye is bent differently, potentially leading to shifts in refractive error, including progression towards myopia (nearsightedness). Diabetes mellitus, on the other hand, can lead to lens swelling due to changes in lens metabolism and fluid changes. This swelling can also increase the refractive index. As the lens becomes more myopic, individuals may find that their distance vision is affected while their near vision may seem to improve temporarily. The other factors mentioned, such as increased lens curvature, reduced lens flexibility, and thickening of the cornea, may also be related to eye health but do not directly address the specific changes in refractive properties associated with cataracts and diabetes in the context of myopia development. Thus, the shift in the refractive index is the most pertinent change to consider in this scenario.