What instrument is typically used for close examination of the eyelids, lashes, cornea, and lens?

The slit lamp, or biomicroscope, is specifically designed for a detailed examination of the anterior segment of the eye, which includes the eyelids, lashes, cornea, and lens. This instrument combines a high-intensity light source with a microscope, allowing the clinician to illuminate and magnify these structures for thorough assessment.

When utilizing the slit lamp, the clinician can view the eye in a variety of ways, such as through a narrow beam of light that can highlight specific areas for closer inspection. This level of detail is crucial for diagnosing conditions affecting these ocular structures, such as infections, neoplasms, or abnormalities in the cornea and lens.

Other instruments do not provide the same level of examination capability for these specific structures. The ophthalmoscope is primarily used for examining the retina and optic nerve but does not focus on the anterior segment. A tonometer measures intraocular pressure and is not intended for structural assessment. The retinoscope is utilized for assessing refractive errors by evaluating how light reflects off the retina, rather than for anatomical examination. Therefore, the slit lamp is the correct choice for this purpose as it is uniquely equipped for the task.