Ophthalmos

Ophthalmos is a term derived from the Greek word ophthalmos, meaning eye. In medical usage, it is most often encountered as part of compounds such as ophthalmoscope and ophthalmoscopy, which refer to the examination of the interior surface of the eye, particularly the fundus.

The ophthalmoscope is the instrument used to illuminate and visualize the eye’s interior. The first practical ophthalmoscope was developed by Hermann von Helmholtz in 1851. Direct ophthalmoscopy employs a light source and magnifying lens to view the retina through a dilated pupil, while indirect ophthalmoscopy uses a condensing lens to produce a wider, though inverted, view of the fundus.

During ophthalmoscopic examination, the observer assesses structures including the optic disc, the macula, retinal vessels, the retina, and the choroid. The interior surface seen is often referred to as the fundus oculi. The examination can be performed with the pupil dilated to improve visualization and may be aided by specialized lenses or imaging devices.

Clinical relevance includes screening and monitoring for ocular diseases such as diabetic retinopathy, hypertensive retinopathy, glaucoma (via optic nerve head changes), age-related macular degeneration, and optic neuritis. It can also reveal signs of systemic conditions, including vascular or hematologic disorders. In modern practice, ophthalmoscopy is complemented by imaging techniques such as fundus photography, fluorescein angiography, and optical coherence tomography, which provide more detailed documentation of retinal and optic nerve structures.