What is the method for checking scleral lenses under fluorescein?

The preferred method for checking scleral lenses under fluorescein involves filling the lens with saline that has been mixed with fluorescein before insertion. This technique allows for an optimal assessment of the lens's fit on the eye. By filling the lens with the fluorescein solution, the clinician can effectively evaluate the relationship between the lens and the cornea through the use of a slit lamp. The fluorescein highlights any areas of compression, pooling, or clearance, helping to identify if the lens is properly positioned and functioning as intended.

Other methods, such as applying fluorescein directly to the eye or inserting the lens without solution, do not provide comprehensive data regarding the fit. Additionally, simply illuminating the lens with a light source does not offer the same visual feedback regarding the interaction between the lens and the cornea that the saline-fluorescein mixture does. Therefore, the correct answer emphasizes a procedure that maximizes diagnostic efficacy in fitting scleral lenses.