What instrument is used to evaluate contact lenses in a patient?

The instrument used to evaluate contact lenses in a patient is the ophthalmoscope. This device is designed to examine the interior of the eye, which includes the retina and the lens, as well as to assess any potential issues related to contact lens wear.

When assessing a patient's contact lenses, an ophthalmologist or optometrist can utilize the ophthalmoscope to look closely for signs of irritation, corneal health, or other ocular conditions that may arise from contact lens use. By providing a clear view of the eye's structures, the ophthalmoscope helps healthcare professionals ensure that the lenses fit properly and are not causing any harm to the patient's eyes.

The other options do not pertain to eye examination:

• A stethoscope is primarily used to listen to heart and lung sounds.

• An otoscope is designed for examining the ears.

• A dermatoscope is utilized for skin examinations.

These tools serve specialized purposes that do not relate to the evaluation of contact lenses or the health of the eye, emphasizing the importance of the ophthalmoscope in this context.