The medial rectus is one of the six extraocular muscles that move each eye. It sits on the nasal (inner) side of the eyeball and pulls the eye inward. Clinicians discuss the medial rectus when evaluating eye alignment, double vision, and strabismus. It is also a key muscle in eye muscle (strabismus) surgery planning.

extraocular muscles are the small skeletal muscles that move each eye within the orbit (eye socket). They work together to aim both eyes at the same target so vision stays single and clear. Clinicians assess extraocular muscles during routine eye exams and when symptoms suggest eye misalignment. They are also central to conditions like strabismus (eye turn) and double vision.

vortex veins are the main veins that drain blood from the eye’s choroid (the vascular layer behind the retina). They collect blood in characteristic “whorled” patterns and exit the eyeball through the sclera (the white outer coat). Clinicians refer to vortex veins when describing normal anatomy, interpreting imaging, and planning surgery near the back of the eye. They are not a treatment—rather, they are an anatomic structure that can help explain certain exam or imaging findings.

The central retinal vein is the main vein that drains blood out of the retina. It travels through the optic nerve and exits the eye at the optic disc. Clinicians refer to it when describing retinal blood flow and retinal vascular disease. It is most commonly discussed in eye exams and imaging for conditions like vein occlusions.

The central retinal artery is the main blood vessel that supplies oxygenated blood to the inner layers of the retina. It is a small artery that enters the eye through the optic nerve and branches across the retinal surface. Clinicians discuss it most often when evaluating retinal circulation and sudden vision loss. It is also a key structure in retinal imaging and in understanding several eye and systemic vascular conditions.

The visual cortex is the part of the brain that processes information from the eyes. It turns light-based signals into what you recognize as shapes, color, motion, and depth. It sits in the back of the brain, mainly in the occipital lobe. It is commonly discussed in eye care, neurology, and neuro-ophthalmology when vision symptoms are not fully explained by the eyes themselves.

The lateral geniculate nucleus is a small, layered structure deep in the brain that relays visual information. It sits in the thalamus and acts like a “switchboard” between the eyes and the visual cortex. It is commonly discussed in neuro-ophthalmology, neurology, optometry, and vision science. Understanding it helps explain certain visual field loss patterns and brain-related vision symptoms.

The optic tract is a bundle of nerve fibers in the brain that carries visual information. It begins just behind the optic chiasm and continues toward deeper brain visual relay centers. It is commonly referenced in neuro-ophthalmology, neurology, and radiology when explaining vision symptoms. It helps clinicians connect visual field changes to specific locations in the visual pathway.

The optic chiasm is a small crossing point where the optic nerves partially swap fibers. It sits at the base of the brain, just behind the eyes and above the pituitary gland. It is essential for normal visual field organization and binocular vision. Clinicians refer to the optic chiasm when explaining certain vision loss patterns and when localizing neurologic disease.

The optic nerve is the cable-like bundle of nerve fibers that carries visual information from the eye to the brain. It begins at the optic disc (the “blind spot”) at the back of the eye and travels toward the brain’s visual pathways. Clinicians use optic nerve findings to understand vision loss, eye pain, and changes in the visual field. It is commonly assessed in routine eye exams and in conditions such as glaucoma and optic neuritis.

lamina cribrosa is a sieve-like layer of connective tissue inside the optic nerve head. It sits where the retinal nerve fibers exit the eye to form the optic nerve. Clinicians most often discuss it when evaluating glaucoma and other optic nerve conditions. It is commonly assessed with modern eye imaging, especially optical coherence tomography (OCT).

In eye care, **cup** most often refers to the central depression within the optic nerve head (the optic disc) seen during an eye exam. It is a normal anatomical feature, but its size and shape can change in certain diseases. Clinicians describe cup appearance to help assess the health of the optic nerve, especially in glaucoma care. The term also appears in clinical documentation, imaging reports, and teaching about optic nerve anatomy.

The neuroretinal rim is the ring of optic nerve tissue seen at the edge of the optic disc (the “optic nerve head”) inside the eye. It represents the nerve fiber bundles that carry visual information from the retina to the brain. Clinicians commonly assess the neuroretinal rim during eye exams and imaging when evaluating glaucoma and other optic nerve conditions. In plain terms, it is the “healthy nerve tissue border” around the optic nerve’s central cup.

The optic nerve head is the visible “front end” of the optic nerve inside the eye. It is the spot where retinal nerve fibers exit the eye to carry visual signals to the brain. Clinicians also call it the optic disc, and it is routinely assessed during eye exams and imaging. Its appearance can provide clues about glaucoma, optic nerve disease, and increased pressure around the brain.

The optic disc is the spot inside the back of the eye where the optic nerve enters the retina. It is sometimes called the optic nerve head in clinical contexts. It is visible during a dilated eye exam and on retinal imaging. Clinicians use optic disc appearance to assess eye and neurologic health.

The choriocapillaris is a thin layer of very small blood vessels in the back of the eye. It sits within the choroid, just beneath the retinal pigment epithelium (RPE). Its main role is to help supply oxygen and nutrients to the outer retina. In modern eye care, it is commonly discussed when interpreting retinal imaging and choroidal disease.

The choroid is a vascular (blood vessel–rich) layer inside the eye. It sits between the retina and the sclera (the white outer coat of the eye). Its main role is to supply oxygen and nutrients to parts of the retina involved in vision. In eye care, the choroid is commonly discussed in retinal imaging, diagnosis, and treatment planning.

The inner plexiform layer is a thin, important layer inside the retina. It is where retinal nerve signals are “wired together” through many tiny connections. Clinicians most often reference it in retinal imaging reports, especially OCT scans. It is also used in teaching and research to explain how vision signals are processed.

The outer plexiform layer is a thin layer inside the retina at the back of the eye. It is where light-sensing cells connect to the next set of retinal nerve cells. It helps the retina begin turning visual information into signals the brain can use. It is commonly discussed in retinal anatomy, optical coherence tomography (OCT), and disease evaluation.

The inner limiting membrane (ILM) is the retina’s innermost surface layer. It forms the boundary between the retina and the vitreous gel inside the eye. Clinicians most often discuss the inner limiting membrane (ILM) in macular diseases seen on OCT scans. It is also a key structure in vitreoretinal surgery, where it may be peeled to relieve retinal traction.