Which tool is used specifically for assessing spectacle prescription?

The retinoscope is the correct tool for assessing spectacle prescriptions because it allows practitioners to objectively measure the refractive error of the eye. This instrument works by projecting a beam of light into the eye and observing the reflection of light off the retina. By utilizing the movement of the reflections (or ‘reflex’) observed, the practitioner can determine the necessary corrective lenses needed for the patient.

Using retinoscopy, the eye care professional can ascertain the power of lenses required for the patient to achieve optimal vision. This process is fundamental in determining whether a patient needs glasses and to what extent, thereby facilitating the creation of an accurate spectacle prescription.

The other tools mentioned serve different purposes in eye care. An ophthalmoscope is mainly used for examining the interior structures of the eye, such as the retina and optic nerve. A slit lamp provides a magnified view of the front structures of the eye, allowing for a thorough examination of the cornea, lens, and anterior chamber. A pupillometer measures the size of the pupils and their reactions to light but does not provide information on refractive error or spectacle prescription.