What type of astigmatism is represented by the following example: K's 44.00 @180/ 44.50 @90; RX -3.00 -2.50 X 180?

The correct answer is that this scenario represents lenticular astigmatism. Lenticular astigmatism occurs when there is an irregular curvature of the lens, as opposed to the cornea. In this case, the prescription indicates a significant cylindrical component (the -2.50 cylinder) at 180 degrees, which implies that there is an astigmatic component related to the lens rather than to the corneal surface.

In interpreting K's or keratometry readings, the values of 44.00 @180 and 44.50 @90 suggest a relatively regular curvature of the cornea, indicating that any astigmatism demonstrated in the prescription is more likely stemming from the lens than the cornea itself. Regular astigmatism, for instance, is characterized by consistent and predictable curvature of the cornea, which is not the primary factor in this example.

Additionally, other forms of astigmatism, such as mixed astigmatism, involve both types of refractive error and don't specifically point to lenticular issues. Since the primary description and resultant prescription predominantly involves cylindrical power that can be attributed to lens irregularities, this confirms that lenticular astigmatism is indeed the correct interpretation of the presented details.