A 32-year old female presents with blurred vision at a distance due to a new medication. Which medication is most likely the culprit?

The medication most likely responsible for the blurred vision at a distance in this scenario is isotretinoin. This medication is commonly used to treat severe acne and can have several side effects, including effects on vision.

Isotretinoin can cause dryness of the mucous membranes and can affect the lacrimal glands, leading to decreased tear production. This can result in dry eyes, which may manifest as blurred vision, especially during activities that require visual acuity, such as driving or reading at a distance. Additionally, isotretinoin has been associated with other visual side effects, including night vision problems and changes in color perception.

In contrast, acetaminophen and calcium carbonate are not typically associated with vision changes, as they do not have known ocular side effects. Omega-III fish oil capsules are generally considered safe and are often used to support eye health, rather than causing visual disturbances. Thus, isotretinoin stands out as the medication that is most likely to cause distance vision issues due to its known ocular side effects.