General terms and accessory structures
English anatomical terminology of the eye largely calques Latin, which makes it easier to memorize. The eye itself is denoted by the word eye, the conjunctiva by conjunctiva, and the lacrimal gland by lacrimal gland (from Lat. glandula lacrimalis, with the adjective placed before the noun in English).
The eye has three tunics, each of which is designated by the word layer:
- fibrous layer — fibrous tunic;
- vascular layer — vascular tunic (uvea);
- neural layer — inner (retinal) tunic, more commonly called retina.
The optic nerve is designated as optic nerve.
Fibrous layer
The fibrous layer comprises two fundamentally important structures:
- cornea — cornea;
- sclera — sclera.
The junction where the cornea transitions into the sclera is called the limbus. Pay attention to the pronunciation of this term, which is close to the Latin variant.
Although the chambers of the eye do not formally belong to the fibrous layer itself, it is convenient to discuss them in this context:
- anterior chamber — anterior chamber, located behind the cornea;
- posterior chamber — posterior chamber, located behind the iris.
The word chamber in relation to the eye is translated precisely as "chamber", while the adjectives anterior and posterior mean "anterior" and "posterior" respectively.
Vascular layer
The vascular layer includes three key structures:
- choroid — choroid proper;
- ciliary body — ciliary body;
- iris — iris (Lat. irides).
The adjective ciliary is actively used in ophthalmological terminology. Associated with it are:
- ciliary muscle — ciliary muscle;
- ciliary processes — ciliary processes (process — process, plural processes);
- suspensory ligaments — suspensory ligaments, also known as the zonule of Zinn (ligament — ligament).
Retina and its structures
The retina features a number of anatomical landmarks and cellular layers:
- fovea centralis (or simply fovea) — central pit;
- macula lutea (or macula) — macula lutea;
- optic disc — optic disc (to be distinguished from optic nerve).
Photoreceptors are represented by two types of cells, each having a pair of synonymous designations:
- rods, or night vision photoreceptors — rods, responsible for scotopic vision;
- cones, or day vision photoreceptors — cones, providing photopic and color vision.
The neuronal organization of the retina also mentions bipolar cells and ganglion cells. The ganglion cell layer is designated as ganglion cell layer, where layer is translated as "layer".
Optical media of the eye
Transparent light-refracting media of the eye include structures that ensure image focusing on the retina:
- lens — lens;
- vitreous body — vitreous body;
- aqueous humor — aqueous humor, filling the anterior and posterior chambers of the eye.
It is advisable to memorize these three terms together, as they form a single optical system of the eye along with the cornea.
Key points
- Three tunics of the eye: fibrous, vascular, and neural layer (retina).
- The fibrous layer is formed by the cornea and sclera; the transition between them is the limbus.
- Chambers of the eye — anterior and posterior chamber; the word chamber in ophthalmology means "chamber".
- The vascular layer consists of the choroid, ciliary body, and iris; the adjective ciliary is used in the terms ciliary muscle, ciliary processes.
- The retina features the fovea centralis, macula lutea, optic disc.
- Photoreceptors: rods (night vision) and cones (day vision).
- Optical media: lens, vitreous body, aqueous humor.
- English terminology is close to Latin, which simplifies learning it for medical professionals.