Glaucoma.
PDE converts cGMP to GMP.
Axons from the nasal part of the retina cross the midline at the optic chiasma.
Loss of recognition of shapes.
An area where no photoreceptors are present, where the optic nerve exits the retina.
Glial cells.
Swelling of the optic disc due to increased intracranial pressure.
To move the eye laterally (abduction).
The superior oblique muscle.
Salt, Acid, Sweet, Umami (Glutamate – amino acids), Bitter substances.
The dorsal stream is involved in the perception and movement of objects in space.
Perimetry is the systematic measurement of vision in the visual field.
Bitter.
Medial Longitudinal Fasciculus.
The limits of the visual field can be mapped to objects or lights of different sizes and brightness.
In darkness, there is an increase in glutamate release.
Contracted arteries.
Refraction errors may reduce the visual acuity.
Hypertension.
36 million people.
By gap junctions.
They have small receptive fields and inform about fine features and color.
Central vision is the part of our vision that is represented by the macula and fovea in the retina, where the highest concentration of cone cells is found.
It can contribute to the development of papilledema.
Abducens nerve (Cranial Nerve VI).
Cataracts are usually caused by aging, but can also result from injury, certain medications, and medical conditions such as diabetes.
In the fovea.
Institute of Biomedicine, Aarhus University.
A reflex that controls the diameter of the pupil in response to the intensity of light reaching the retina.
It can cause horizontal gaze palsy, affecting the ability to move both eyes in the horizontal direction.
It is the origin of the trochlear nerve, which controls the superior oblique muscle of the eye.
Visual acuity measures the central visual resolution of the retina.
Dura, arachnoid, and pia mater.
A small bright circle of light surrounded by a darker circle.
The blind spot is an area on the retina where the optic nerve exits the eye, and it has no photoreceptor cells, meaning no image detection occurs there.
It is converted to trans-retinal, activating the opsin molecule.
Retina, Choroid, and Sclera.
A real image behind the lens.
Scotopic (low-light) for rods and photopic (daylight) for cones.
Bilateral loss of parts of the central visual field.
It decreases the excitation of horizontal cells.
It is the reflexive change in the size of the pupil in response to light.
Rods are responsible for scotopic (night) vision.
Hyperopia.
The transduction channels close, decreasing a Na+ current.
In the hypothalamus and mesencephalon.
It connects the vestibular nuclei with all the nuclei involved in eye movements.
In rods, the membranes are located within the cell, while in cones, they are folds of the outer membrane.
The olfactory system (smell) and the gustatory system (taste).
Defects in the visual field are areas where vision is lost or reduced, which can be caused by various conditions affecting the eye or visual pathways.
A prominent sulcus (groove) in the occipital lobe of the brain.
In the occipital lobe of the brain.
The superior oblique muscle of the eye.
The density of photoreceptors.
Opsin (a protein) and Retinal (an aldehyde of vitamin A).
The ora serata is the peripheral edge of the retina.
A small dark circle of darkness surrounded by a lighter circle.
A cataract is a clouding of the lens in the eye, leading to a decrease in vision.
Parietal and Frontal Cortex.
The area of the visual field outside the central visual field, responsible for detecting motion and providing context to the central vision.
Hypertension.
Inner and Outer layers.
In the midbrain, at the level of the superior colliculus.
As positive dioptre.
Oculomotor nerve (Cranial Nerve III).
It impairs the ability to detect light in the right eye, affecting the pupil's response.
They connect the eye motor nuclei in the brainstem.
The inferior rectus.
Clinical notes refer to observations and recordings made by healthcare professionals regarding a patient's visual health.
Cortical defects refer to impairments in the visual processing areas of the brain, which can affect how visual information is interpreted.
The lateral parts of the parietal, occipital, and posterior temporal lobes.
Dura, arachnoid, and pia mater.
The visual field is divided into the right eye visual field and the left eye visual field.
At the optic disc.
Myelination, which helps in the efficient transmission of visual signals.
It can lead to papilledema by compressing the central vein in the optic nerve.
The blind spot occurs because it is the point where the optic nerve exits the eye and there are no photoreceptors (rods or cones) in this location.
Hypertension.
It is a pigmented cell layer that nourishes retinal visual cells.
It is reduced.
Frontal and Parietal Cortex.
Into upper and lower visual fields.
Papilledema is the swelling of the optic disc due to increased intracranial pressure; it can be a complication of severe hypertension.
Brightness, pupil responses, and circadian rhythms.
It elevates the eye.
The VI Abducens Nerve controls the lateral rectus muscle, which is responsible for moving the eye outward.
Medial rectus muscle.
Risk factors include aging, diabetes, smoking, prolonged exposure to sunlight, and excessive alcohol consumption.
Bitemporal hemianopsia.
Coordinates activity between the various nuclei involved in eye movements.
The photopigment in rods is called rhodopsin, which is most sensitive to blue light.
Glutamate.
Blindness for movements.
It can lead to internuclear ophthalmoplegia, which affects coordinated eye movements and causes double vision.
The primary visual cortex (V1).
It is the primary visual processing center in the brain.
10 layers.
Cribriform lamina of sclera.
The brain stem integrates signals from the cranial nerves and coordinates eye movements.
Transducin activates phosphodiesterase (PDE).
Loss of vision in the same quadrant of the visual field for both eyes.
Vitreous body.
Vestibular Nuclei and Cerebellum.
Injury to the left Medial Longitudinal Fasciculus (MLF).
Normal.
Nasal ipsilateral hemianopsia.
An imaginary image in front of the lens.
The Abducens Nucleus is located in the pons, in the brainstem.
Myopia, or nearsightedness, is a refractive error where distant objects appear blurry because the eye focuses images in front of the retina.
Some bipolar cells are depolarized and activated by photoreceptors, while others are hyperpolarized.
Cells that respond to specific orientations of visual stimuli.
In the lower part of the striate cortex.
Cones contain one of three different cone opsin molecules that are sensitive to blue, green, or red light.
The ora serrata is the serrated junction between the optic part of the retina and the ciliary part of the retina.
Myopia.
The sclera is the white, outer layer of the eye that provides structure and protection.
A reflex action resulting in the automatic closing of the eyelid when the cornea is stimulated.
It can lead to an inability to move the eye laterally, resulting in double vision or strabismus.
A reflex action of the eye in response to focusing on a near object, then looking at a distant object, and vice versa, involving changes in lens shape, pupil size, and eye convergence.
In the fovea.
cAMP activated Na+ channels are open and the rod and cones are depolarized.
In light, the photoreceptors are hyperpolarized.
It refers to the mapping of visual input from the retina to neurons, particularly those in the visual cortex, maintaining the spatial organization of the visual field.
In light, there is a decrease in glutamate release.
Muscles of the eye, cranial nerves, brain stem, and cortex.
Cranial Nerve IV or IV Trochlear Nerve.
They are involved in lateral inhibition.
The central field and the peripheral field.
Color, forms, and face recognition.
GABA.
Rods and cones.
Cranial nerves III (oculomotor), IV (trochlear), and VI (abducens).
The lingual and the occipitotemporal gyri.
Because it lacks photoreceptors.
The G-protein transducin, converting GTP to GDP.
The left medial rectus muscle.
About 10%.
Common symptoms include blurry vision, difficulty seeing at night, sensitivity to light, and seeing halos around lights.
At a positive focal point.
Rods are located in the peripheral retina, while cones are concentrated in the central retina.
They have big receptive fields and inform about movements and contrast.
Mostly in the peripheral regions and not in the fovea.
Central vision.
It is the swelling of the optic disc due to increased intracranial pressure.
They facilitate the movement of the eye in different directions.
It is a space between the arachnoid and pia mater.
Vestibular Ocular and Optokinetic.
The area of the visual field that corresponds to the macula, responsible for high-acuity vision.
It increases pressure in the subarachnoid space, leading to compression of the central vein in the optic nerve and increased venous pressure.
Controls most of the eye's movements, the constriction of the pupil, and maintains an open eyelid.
Retina, choroid, and sclera.
Phototransduction.
The Oculomotor Nerve (Cranial Nerve III).
The Oculomotor Nerve.
Blind on the affected eye.
It controls the parasympathetic innervation of the pupil and lens.
The point where the optic nerve exits the eye.
In the left hemisphere.
It impairs the ability to constrict the pupil in the right eye, resulting in a lack of pupil response.
Rapid eye movements that change the point of fixation.
It relays parasympathetic signals to the pupil sphincter muscle to control pupil constriction.
The left visual field.
Pathways that transmit visual information from the retina to the primary visual cortex.
The optic tract is the part of the visual pathway that carries information from the optic chiasma to the brain hemispheres.
Abducens nerve.
It transmits sensory information to the spinal nucleus.
Superior Colliculus.
It controls the lateral rectus muscle, which abducts the eye.
Presbyopia is caused by the natural aging of the eye's lens, leading to difficulty focusing on close objects.
Medial Longitudinal Fasciculus.
Myopia is typically corrected with concave (minus) lenses or refractive surgery.
Inability to move the left eye laterally (to the left).
The dorsal stream (where pathway) and the ventral stream (what pathway).
The cortex processes visual information and sends commands to the brain stem and eye muscles to direct eye movements.
The blind spot appears in the right eye as seen from above.
They include the Inner and Outer Limiting Membranes.
There is decreased inhibition of the rods and cones by horizontal cells.
Light hyperpolarizes photoreceptor cells and reduces the release of glutamate from their synaptic terminals.
Loss of facial recognition.
The right visual field.
There may be misalignment of the eyes, with the left eye potentially deviating outwards.
The risk can be reduced by wearing sunglasses, not smoking, limiting alcohol consumption, and managing health conditions like diabetes.
Contralateral homonym hemianopsia.
Hyperopia, or farsightedness, is a refractive error where close objects appear blurry because the eye focuses images behind the retina.
The Facial Nucleus is located in the pons, in the brainstem.
Oculomotor Nerve (Oculomotor N.).
Depolarization arises when glutamate binds to ionotropic AMPA receptors on the dendrites.
Retina.
The optic part of the retina is the portion of the retina that contains photoreceptors and is involved in image formation.
Rods and Cones.
At the optic chiasm.
It coordinates the movement of the eyes by connecting different eye movement nuclei.
About 40 dioptres.
The retina is the light-sensitive layer at the back of the eye that converts light into neural signals.
Visual Field Right Eye and Visual Field Left Eye both process information contralaterally in the brain.
Visual Pathways.
Processing form and shapes, as well as color.
Visual Cortical Areas.
It coordinates the motor response to the cornea reflex, leading to blinking.
It regulates vital functions such as heart rate, breathing, and blood pressure.
M ganglion cells are involved in motion detection and low contrast sensitivity.
It refers to the opposite side of the body.
The pigment epithelium is a layer of cells behind the retina that nourishes retinal visual cells and absorbs stray light.
Scleral venous sinus (Schlemm’s canal).
Cataracts.
Cataracts can be treated with surgery, which involves removing the cloudy lens and replacing it with an artificial one.
Cones are responsible for photopic (day) vision.
The left eye will not be able to adduct due to the paralysis of the left medial rectus.
Glutamate.
The visual cortex is modularly organized.
At a virtual and negative focal point.
Frontal Eye Field (FEF).
It moves the eye laterally.
As negative dioptres.
The primary visual cortex.
To the lateral geniculate nucleus (LGN) of the thalamus.
Contralateral homonym hemianopsia (macula sparing).
In the Spinal Nucleus of the Trigeminal Nerve (Spinal Nucl. n. V).
Cells that respond preferentially to input from one eye over the other.
The Reticular Substance.
The fovea is a small central pit in the retina responsible for sharp central vision.
The Ocular Orbicular Muscle.
Frontal Eye Field, Supplementary Eye Field, Association Areas, Pontine Nuclei, Flocculus, MLF, Vestibular Nuclei, Abducens Nucleus, Oculomotor Nucleus.
About 20 dioptres.
Thalamus.
To process object recognition and form (the 'what' pathway).
Pronounced Strabismus.
The Stratum Plexiforme Internum, or Inner Plexiform Layer, is a layer where bipolar cells synapse with ganglion cells.
In the occipital lobe, it is part of the primary visual cortex.
The Abducens Nerve (Cranial Nerve VI).
Medial Longitudinal Fasciculus.
It refers to the same side of the body.
It is the fluid in the eye that helps maintain intraocular pressure and nourishes the eye tissues.
Dilator pupillae.
Sympathetic trunk.
Accommodation.
Retina and Occipital Cortex.
It is the innermost layer of the choroid, located between the choroid and the retinal pigment epithelium.
To transmit visual information from the retina to the brain for processing.
It coordinates eye movements by connecting the abducens nucleus with the oculomotor nucleus.
At the optic chiasm.
Supplementary Eye Field and Parietal Eye Field.
The optic nerve carries visual information from the retina to the optic chiasma.
Astigmatism is a refractive error caused by an irregular shape of the cornea or lens, leading to blurred or distorted vision at all distances.
It allows coordination between different cranial nerve nuclei to ensure smooth and synchronized eye movements.
It carries axons from the upper part of the visual field to the lower part of the striate cortex.
The FLM is responsible for coordinating eye movements by connecting the vestibular nuclei with the nuclei of the extraocular muscles.
The Calcarine Sulcus.
The right visual field.
The Pulvinar is involved in visual processing and attention, although it is not part of the primary visual pathway.
Retina cells.
Cylindrical lenses are used to correct astigmatism.
Strabismus.
The central artery and vein supply blood to and drain blood from the retina, respectively.
It relays visual information from the retina to the visual cortex.
Ophthalmoscopic examination, or fundoscopy, is a test that allows a doctor to see inside the back of the eye, including the retina, optic disc, macula, and blood vessels.
0.083 meters.
The pons acts as a bridge connecting different parts of the brain and plays a role in sleep and arousal.
Pigment epithelium.
Ganglion cells.
They are fibers that connect the ciliary body to the lens and help to hold the lens in place.
Rods and cones.
Cones.
It is where bipolar cells synapse with ganglion cells.
External plexiform layer.
The sclera is the white, outer layer of the eye that provides protection and structure.
The lens focuses light onto the retina for clear vision.
Glaucoma is a group of eye conditions that damage the optic nerve, often due to high intraocular pressure.
The Facial Nerve controls the muscles of facial expression and provides taste sensations from the anterior two-thirds of the tongue.
The left eye may have normal function, but there might be issues with the right eye adducting.
Light -> Retina -> Optic Nerve -> Optic Tract -> Pretectal Area -> Accessory Oculomotor Nucleus -> Oculomotor Nerve -> Pupil Sphincter Muscle.
They are organized in columns perpendicular to the cortical surface.
Optic Nerve → Optic Tract → CGL (Lateral Geniculate Nucleus) → Optic Radiation → Calcarine Sulcus
FLM stands for the Medial Longitudinal Fasciculus.
It transmits visual information from the retina to the brain.
The LGN acts as a relay center, processing and transmitting visual information to the visual cortex.
The Dorsal Stream and The Ventral Stream.
The scleral venous sinus (Schlemm's canal) drains aqueous humor from the anterior chamber of the eye into the bloodstream, helping to maintain intraocular pressure.
In the occipital lobe of the brain.
Hyperopia is typically corrected with convex (plus) lenses or refractive surgery.
The right eye would move right, but the left eye would not move.
The optic disc is the point of exit for ganglion cell axons leaving the eye. It is also known as the blind spot because it contains no photoreceptors.
Optic radiations.
The retina is the light-sensitive layer at the back of the eye that converts light into neural signals, which are then sent to the brain.
Approximately 60 dioptres.
Optic Tract.
The Stratum Nucleare Internum, or Inner Nuclear Layer, contains cell bodies of bipolar cells, horizontal cells, and amacrine cells.
Primary visual cortex.
The midbrain is involved in functions such as vision, hearing, eye movement, and body movement.
It controls essential functions such as breathing, heart rate, and blood pressure, which are necessary for life.
Movements and spatial relationships.
The reticular formation is involved in regulating the sleep-wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli.
They are part of the iris.
Anterior chamber.
It is the fluid-filled space between the cornea and the lens, containing aqueous humour.
Accommodation involves the contraction of the ciliary muscle, which reduces the tension in Zonular fibers, allowing the lens to become rounder for focusing on nearby objects.
They can lead to complications such as retinopathy and other vision problems.
Refraction.
Hyperpolarization arises when glutamate binds to the metabotropic receptor mGluR6 on the dendrites.
Contralateral homonym upper quadrant hemianopsia.
The Abducens Nerve.
It processes visual information received from the optic tract before relaying it to the visual cortex.
The optic chiasma is where the axons from the nasal part of the retina cross the midline.
The sclera is the white outer layer of the eyeball that provides protection and form.
In the Thalamus.
The ciliary part of the retina is the non-photosensitive part that continues from the optic part and is involved in producing aqueous humor.
M cell layers.
The ciliary body is a circular structure in the eye that produces aqueous humor and contains muscles that control the shape of the lens for focusing.
Processing movements and spatial relationships.
To process spatial awareness and the location of objects (the 'where' pathway).
The left eye might deviate medially (inward).
The Facial Nerve (Facial N.).
The medulla oblongata, pons, and midbrain.
In the occipital lobe.
Abducens Nerve palsy.
Smell.
Taste.
Injury to the Left Abducens Nerve.
They are types of cells in the LGB that respond differently to light stimuli; ON-centre cells are excited by light in the centre and inhibited by light in the surround, while OFF-centre cells are the opposite.
Nerve fiber layer.
Convergence of the eye.
Amacrine cells.
Posterior chamber.
It drains aqueous humour from the anterior chamber to maintain intraocular pressure.
Pigment epithelium.
Ganglion cell layer.
The lateral rectus muscle moves the eye laterally (away from the nose).
Trigeminal Nerve (Trigeminal N.).
The vitreous body is the clear gel that fills the space between the lens and the retina in the eyeball.
Accommodation.
Ciliary processes are folds on the inner surface of the ciliary body that secrete aqueous humor.
Cells responding to colour are grouped in small areas called colour blobs.
It elevates the upper eyelid.
Oculomotor Nucleus (III), Abducens Nucleus (VI), and Paramedian Pontine Reticular Formation (PPRF).
No, photoreceptors and bipolar cells do not generate action potentials.
To the primary visual cortex (V1) in the occipital lobe.
The lateral geniculate nucleus (LGN) of the thalamus.
Ganglion cells are neurons that relay information from the retina to the brain via the optic nerve.
The Principal Nucleus of the Trigeminal Nerve (Principal Nucl. n. V).
To smoothly follow moving objects with the eyes.
The Optic Tract.
Chiasma.
It is part of the Optic Radiation.
Eye Movements.
The macula is a small central area of the retina that is responsible for central vision and high acuity vision.
'Stave og tappe' translates to rods and cones, which are the photoreceptor cells in the retina responsible for vision.
The Dorsal Stream.
Form, shapes, and color.
The sclera is the white outer layer of the eyeball that provides structure and protection.
Bipolar cells.
The lens focuses light onto the retina to form clear images.
Rods.
Photosensitive layer.
Cell bodies of photoreceptors (rods and cones).
Choroidea.
The iris controls the size of the pupil and thus the amount of light reaching the retina.
Vision under low light conditions, primarily mediated by rods.
The outer segments of rods and cones contain highly folded membranes with the photopigment.
ON and OFF ganglion cells are excited by either ON or OFF bipolar cells and generate action potentials.
The left visual field.
Approximately 60 dioptres.
Photo-Transduction.
The fovea is a small depression in the retina where visual acuity is highest. It is densely packed with cone photoreceptors.
P cell layers.
Aqueous humor is a clear fluid produced by the ciliary processes that fills the anterior and posterior chambers of the eye, providing nutrients and maintaining intraocular pressure.
Retina.
Presbyopia is commonly corrected using reading glasses, bifocal or multifocal lenses, or contact lenses.
Optic nerve.
Uncorrected astigmatism can lead to headaches, eye strain, and blurred or distorted vision.
Lateral geniculate body.
Sphincter pupillae.
Oculomotor nerve.
Superior colliculus and pretectal area.
The vitreous body helps maintain the shape of the eye and provides support to the retina.
Superior ganglion.
Horizontal cells integrate and regulate input from multiple photoreceptors.
The cornea is the transparent front part of the eye, and it helps focus incoming light.
Cones are responsible for color vision and high-acuity (photopic) vision.
In the presence of light, photoreceptor cells become hyperpolarized and reduce neurotransmitter release.
Rods are more numerous and are found predominantly in the peripheral retina, while cones are concentrated in the fovea.
The optic nerve transmits visual information from the retina to the brain.
The retina is the light-sensitive layer of tissue at the back of the eye that converts light into neural signals.
The posterior chamber is the fluid-filled space between the iris and the lens.
The central retinal artery supplies blood to the retina, and the central retinal vein drains blood from the retina.
Red cones.
It acts as a relay center, processing visual information before sending it to the visual cortex.
The Stratum Plexiforme Externum, or Outer Plexiform Layer, is a layer in the retina where photoreceptors connect with bipolar and horizontal cells.
By 12 to 13 dioptres.
The Stratum Nucleare Externum, or Outer Nuclear Layer, contains the cell bodies of the photoreceptors (rods and cones).
The left eye would be unable to move left, while the right eye might still move.
The Oculomotor Nerve (Cranial Nerve III).
To process and interpret visual information received from the eyes.
The Ventral Stream.
Visual association areas.
Acetylcholine (ACh).
Cranial nerves III to XII are associated with the brain stem.
Medialis rectus, ciliary muscle, and pupillary sphincter.
Photo-transduction.
Pupil constriction.
The retina is the light-sensitive layer that converts light into neural signals sent to the brain.
Ciliary muscles.
Pupil.
The pupil regulates the amount of light that enters the eye.
The fovea centralis is a small pit in the retina that provides the clearest vision by having a high concentration of cones.
The ability to perceive all colors correctly, using blue, green, and red cones.
The choroidea, or choroid, is the vascular layer of the eye situated between the retina and the sclera, providing oxygen and nutrients to the outer retina.
Oculomotor nucleus and accessory oculomotor nucleus.
The ciliary body consists of glands and ciliary muscles.
Noradrenaline.
Rods are responsible for low-light (scotopic) vision.
In the dark, photoreceptor cells are depolarized and release neurotransmitters.
Rhodopsin in rods and photopsins in cones.
Stroma.
The ciliary body produces aqueous humor and contains the ciliary muscle, which controls the shape of the lens.
The sclera is the white part of the eye that provides structure and protection.
The medial rectus muscle moves the eye medially (towards the nose).
The visual axis is an imaginary line that passes through the optical centers of the eye to the fovea centralis.
Vision under well-lit conditions, primarily mediated by cones.
A type of color blindness where individuals cannot perceive blue colors.
The choroid is a vascular layer of the eye that provides oxygen and nutrients to the retina.
Contraction of the ciliary muscle reduces the diameter of the ring it forms around the lens, reducing tension in the Zonular fibers, allowing the lens to obtain a rounder form.
The choroid provides oxygen and nutrients to the outer layers of the retina.
The anterior chamber is the fluid-filled space between the cornea and the iris.
The conjunctiva is the membrane that covers the white part of the eye and the inner surfaces of the eyelids.
Green cones.
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber.
The optic disc is also known as the blind spot.
A type of color blindness where individuals cannot perceive green colors.
The vitreous body is the clear gel that fills the space between the lens and the retina.
A type of color blindness where individuals cannot perceive red colors.
Blue cones.
