Allergic Conjunctivitis (Eye Allergies): a condition occurring when eyes react to something irritating them. The eyes become red, swollen, watery and itchy. The condition is usually temporary, associated with seasonal allergies. Severe allergic eye symptoms can be extremely annoying and are a common reason for visits to an allergist, ophthalmologist, and even the emergency room.

Amblyopia (Lazy Eye): loss or lack of development of central vision in an eye that has no health related problems and is not correctable with glasses. It is most often due to crossed eyes or a large difference in the amount of nearsightedness or farsightedness between the two eyes.

Astigmatism: a defect of an ocular structure (most commonly the cornea or the crystalline lens) causing rays from a point to fail to meet in a single focal point, resulting in an imperfect blurred or smeared image. For example, astigmatism may result if the cornea is more oval than round.

Blepharitis: inflammation, redness, burning, and itching of the eyelids, most commonly in adults, that can be associated with a low grade bacterial infection or a generalized skin condition.

Cataract: a clouding of the crystalline lens of the eye or its surrounding transparent membrane. It causes light to be obstructed or scattered throughout the eye resulting in blurry, hazy, or distorted vision.

Chalazion: an inflamed lump on the eyelid formed by retention of Meibomian gland secretions (oil). The inflammation usually subsides, but may need surgical removal.

Choroiditis (posterior uveitis): inflammation of the choroid (the underlying bed of the retina).

Color Deficiency: an inability to distinguish some colors and shades. It occurs when the color-sensitive cone cells in the retina do not properly pick up or send normal color signals to the brain.

Conjunctivitis (Pink Eye): infection and inflammation of the conjunctiva (the mucous membrane that lines the inner surface of the eyelids and the sclera on the front of the eyeball), usually from an allergy, a virus, or a bacterium.

Crossed Eyes (Strabismus): a visual disorder where the eyes are misaligned due to some type of muscle imbalance in one eye, causing that eye to turn in, out, up, or down relative to the other eye.

Diplopia: double vision, usually caused by a strabismus (a visual disorder where the eyes are misaligned due to some type of muscle imbalance in one eye, causing that eye to turn in, out, up, or down relative to the other eye).

Diabetic Retinopathy: changes in the retina due to uncontrolled diabetes. There are two types of diabetic retinopathy. Non proliferation diabetic retinopathy (NPDR) is an early stage where retinal blood vessels weaken which leads to microaneurisms, causing vision loss. Proliferative diabetic retinopathy (PDR) involves the growth of new blood vessels out of the retina, which leads to the formation of scar tissue and/or the leaking of blood into the eye, causing severe vision loss or blindness.

Dry Eye: a chronic lack of sufficient lubrication and moisture in the eye, causing sensations of dryness, scratchiness or burning. It can be caused by many things that are all related to tear film abnormalities. It occurs more often in women and becomes more common as you age.

Endophthalmitis: an inflammation of tissues inside the eye, usually caused by bacteria or fungi.

Episcleritis: an inflammation (usually localized) of the episclera, a thin layer of tissue covering the sclera and containing many blood vessels that nourish the sclera which is the white, fibrous, protective, external layer of the eye.

Eye Allergies (Allergic Conjunctivitis): a condition occurring when eyes react to something irritating them. The eyes become red, swollen, watery and itchy. The condition is usually temporary, associated with seasonal allergies. Severe allergic eye symptoms can be extremely annoying and are a common reason for visits to an allergist, ophthalmologist, and even the emergency room.

Farsightedness (Hyperopia): a condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects.

Flashes (Photopsia): the brief perception of light that is purely subjective and accompanies a pathological condition, especially of the retina or brain.

Floaters (Muscae Volitantes): bits of optical debris (such as dead cells or fibrils), usually in the vitreous humor, that may be perceived as spots, spiders or mesh before the eyes.

Glaucoma: a progressive disease of the optic nerve, resulting in a reduction in the visual field and even blindness. The most significant risk factor is elevated intraocular pressure (IOP), which results from less fluid leaving the eye than is entering the eye.

Graves' Eye Disease: an autoimmune thyroid condition that often attacks the eye muscles and connective tissue within the eye socket. The disease is found 5 or 6 times more frequently in women than men.

Hemorrhage, subconjunctival: leakage of blood from blood vessels underneath the conjunctiva, often due to a sudden jolt from blunt trauma, coughing, or sneezing. Normal reabsorption of blood usually takes 1-2 weeks.

Herpes Zoster Ophthalmicus (Shingles): involves the orbit of the eye and is caused by the virus reactivating in the ophthalmic division of the trigeminal nerve. In some people, symptoms may include conjunctivitis, keratitis, uveitis, and optic nerve palsies that can sometimes cause chronic ocular inflammation, loss of vision, and debilitating pain.

Hordoelum (Sty or Stye): an inflamed swelling of a sebaceous gland at the margin of an eyelid.

Hyperopia (Farsightedness): a condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects.

Hyphema: a hemorrhage in the anterior chamber of the eye.

Iridocyclitis (intermediate uveitis): inflammation of the iris and the ciliary body.

Iritis (anterior uveitis): inflammation of the iris.

Keratitis: inflammation of the cornea. It often occurs after a corneal trauma with a foreign body (including contact lenses), and with dry eyes or an eyelid disease which allows bacteria or fungi to enter the cornea.

Keratoconus: a degenerative corneal disease characterized by generalized thinning and cone-shaped protrusion of the central cornea. It is hereditary and usually occurs in both eyes.

Lazy Eye (Amblyopia): loss or lack of development of central vision in an eye that has no health related problems and is not correctable with glasses. It is most often due to crossed eyes or a large difference in the amount of nearsightedness or farsightedness between the two eyes.

Legal Blindness / Low Vision: a loss of eyesight (usually indicated by vision of less than 20/200) that can't be improved with eyeglasses, medicine or surgery. Everyday tasks become more difficult to accomplish, causing a person to find new ways to do them. Low vision aids and low vision rehabilitation can empower a person to maintain much of their independence.

Macular Degeneration: a degenerative process of the cells in the central area of the retina (the macula). It reduces the central part of the field of vision as opposed to the peripheral vision. There are two common types of macular degeneration. Dry macular degeneration affects 90% of those with the disease, and wet macular degeneration affects about 10%, but can be more devastating than dry.

Migraine (Classic): a chronic neurovascular disorder characterized by moderate to severe headaches usually affecting one half of the head, lasting 2 - 72 hours and often associated with nausea. The headache is associated with a visual aura that occurs before or during the headache. It is characterized by partial alterations in the field of vision which can flicker, zig zag, appear as flashing lights, sometimes accompanied by sensations of smoked glass or tunnel vision.

Migraine (Retinal ): a retinal migrane is a symptom of a retinal disease typically affecting only one eye. It is caused by a vascular spasm in or behind the affected eye. (see below: Retinal Migrane)

Migraine (Silent): a silent migrane is a classic migrane including a visual aura symptoms and without the headache symptoms.

Muscae Volitantes (Floaters): bits of optical debris (such as dead cells or fibrils), usually in the vitreous humor, that may be perceived as spots before the eyes.

Myopia (Nearsightedness): a condition in which visual images come to a focus in front of the retina of the eye and vision is better for near than for far objects.

Nearsightedness (Myopia): a condition in which visual images come to a focus in front of the retina of the eye and vision is better for near than for far objects.

Nystagmus: involuntary, rhythmical, repeated oscillations of one or both eyes, in any or all fields of gaze.

Optic Neuritis: inflammation of the optic nerve within the eyeball (papillitis) or behind the eyeball (retrobulbar optic neuritis).

Photophobia: an abnormal sensitivity to light, sometimes causing discomfort. It often results from an inflammation of the cornea or iris.

Photopsia (Flashes): the brief perception of light that is purely subjective and accompanies a pathological condition, especially of the retina or brain.

Pinguecula: a yellowish nodule in the conjunctiva at the front of the eye, usually but not always on the nasal side. It is thought to represent degeneration in the conjunctiva as a result of dryness, as well as of exposure to wind and dust.

Pink Eye (Conjunctivitis): infection and inflammation of the conjunctiva (the mucous membrane that lines the inner surface of the eyelids and the sclera on the front of the eyeball), usually from an allergy, a virus, or a bacterium.

Posterior Vitreous Separation (PVS): pulling away or shrinking of the vitreous (the gel-like substance that fills the interior of the eye) from the retinal surface causing flashes and floaters.

Presbyopia: a visual condition which becomes apparent most often after the age of 45 in which loss of elasticity of the crystalline lens causes reduced accommodation and the inability to focus sharply at a near distance without the use of magnifying reading glasses.

Protanopia: a type of color deficiency in which the spectrum is seen in tones of yellow and blue with confusion of red and green and reduced sensitivity to monochromatic lights from the red end of the spectrum.

Pterygium: a wedge-shaped fleshy mass of thickened conjunctiva occurring usually on the inner aspect of the eyeball, covering part of the cornea, and often causing a disturbance of vision due to corneal distortion. They are benign growths most commonly caused by exposure sunlight.

Ptosis: a paralytic drooping of an eyelid.

Red Eye: a term used to describe an eye that appears red due to illness, injury, or some other condition. There are many possible causes of a red eye. The most common is conjunctivitis. Others include blepharitis, acute glaucoma, injury, subconjunctival hemorrhage, keratitis, iritis, episcleritis, scleritis, inflamed pterygium, inflamed pinguecula, dry eye syndrome, airborne contaminants, a burst blood vessel, tick borne illnesses like Rocky Mountain spotted fever, high stress levels and drug use including cannabis.

Retinal Detachment: a separation of the retina from the underlying supportive tissue, often initiated by a retinal tear. Observation of sudden spots, floaters, flashes of light, and/or a web moving in your field of vision indicate the possibility of retinal detachment.

Retinal Migrane: a migraine where there are repeated attacks of visual disturbances preceding the headache phase. Attacks begin with monocular visual symptoms, where each eye is used separately,like scintillations (sparks or flashes), scotoma (areas of depressed vision) or temporary blindness. The headache phase begins within 1 hour of the original symptoms and lasts 4 to 72 hours.

Retinitis Pigmentosa: degeneration of the retina manifested by night blindness and gradual loss of peripheral vision, eventually resulting in tunnel vision or total blindness.

Shingles (Herpes Zoster Ophthalmicus): involves the orbit of the eye and is caused by the virus reactivating in the ophthalmic division of the sensory nerve supplying the eye and surrounding structures. In some people, symptoms may include conjunctivitis, keratitis, uveitis, and optic nerve palsies that can sometimes cause chronic ocular inflammation, loss of vision, and debilitating pain.

Strabismus (Crossed Eyes): a visual disorder where the eyes are misaligned due to some type of muscle imbalance in one eye, causing that eye to turn in, out, up, or down relative to the other eye.

Sty or Stye (Hordoelum): an inflamed swelling of the sebaceous glands of Zeis, located in an eyelash follicle on the margin of an eyelid.

Subconjunctival Hemorrhage: leakage of blood from blood vessels underneath the conjunctiva, often due to a sudden jolt from blunt trauma, coughing, or sneezing. Normal reabsorption of blood usually takes 1-2 weeks.

Tritanopia: a type of color deficiency marked by confusion of blue and yellow.

Uveitis: inflammation of any or all of the structures contained in the uvea (including the iris, ciliary body and choroid).