Increase in optical power by the eye in order to maintain a clear image (focus) as objects are moved closer.

After-cataract, secondary cataract

Remnants of an opaque lens remaining in the eye, or opacities forming, after extra-capsular removal.

Age-related macular degeneration (AMD,ARM)

Group of conditions that include deterioration of the macula, resulting in loss of sharp central vision. Two general types: “dry”, which is more common, and “wet”, in which abnormal new blood vessels grow under the retina and leak fluid and blood, further disturbing macular function. Most common cause of decreased vision after age 60.

Amblyopia “lazy eye”

Decreased vision in one or both eyes without detectable anatomic damage in the eye or visual pathways.Usually uncorrectable by eyeglasses or contact lenses.

Amsler grid

Test card; grid (black lines on white background or white lines on black background) used for detecting central visual field distortions or defects, such as in macular degeneration.

Angle, anterior chamber angle

Junction of the front surface of the iris and back surface of the cornea, where aqueous fluid filters out of the eye.

Anterior chamber

Fluid-filled space inside the eye between the iris and the innermost portion of the corneal.


Absence of the eye’s natural  crystalline lens.

Aqueous, aqueous humor

Clear, watery fluid that  fills the space in the anterior chamber. Produced by the ciliary processes.Factor in intraocular pressure for all patients especially glaucoma patients.


Vague eye discomfort arising from use of the eyes; may consist of eyestrain, headache, and/or brow ache. May be related to uncorrected refractive error or poor ability of the eyes to fuse an image.


Refractive power concern in which light enters the eye and is focused in various places (meridians) within the eye. This prevents formation of a sharp image focus on the retina.Uncorrected astigmatism may result in significant blurred vision and headache.


Eyeglasses that incorporate two different correcting powers in each lens; usually for near and distance corrections.

Binocular vision

Seemless blending of each eyes separate images meshed into one multi-dimensional image/scene.


Typically a chronic inflammatory condition of the eyelids which may involve crusting, burning, itching, and other symptoms.

Blind spot

Normal area within a person’s field of vision that is devoid of any vision.Anatomically due to an absence of light sensitive photoreceptors where the optic nerve enters the eye.


Type of ultrasound; provides a cross-section view of tissues that cannot be seen directly.


Opacity or cloudiness of the natural  crystalline lens. There are many types of cataracts, each over time impact quality of vision.  Surgical removal of the lens may be necessary  and is generally replaced with an intraocular lens, contact lens, or aphakic spectacles. Most common etiologies are: advanced age, health issues, medications, trauma, and congenital.

Central vision

An eye’s best vision; used for reading and discriminating fine detail and color.Results from stimulation of the fovea and the macular area.


Infection of a meibomian gland (in the eyelid). May be treated with oral and or topical medications. On occasion, may need minor surgical intervention.

Color blindness

Reduced or the absence to discriminate between certain colors like red, green, and rarely blue.


Light-sensitive retinal receptor cell provides sharp visual acuity and color discrimination.


Transparent membrane covering the outer surface of the eyeball and also lines the inner eyelid surface.

Conjunctivitis, “pink eye”

Inflammation of the conjunctiva.Characterized by discharge, redness and swelling.May be viral, bacterial or allergic. If viral, it can be contagious.


The movement of both eyes inward.


Transparent front part of the eye that covers the iris, pupil, and where a contact lens sits upon.


(see esotropia) is a form of strabismus (involuntary eye turn) wherein one or both eyes turns inward.

Crystalline lens

The eye’s natural lens and main structure to help us focus. Clear when young and begins to cloud as we mature.

Cycloplegic refraction

Assessment of a dilated eye’s refractive error (prescription) as the eye’s focusing system is now at rest.

Diabetic retinopathy

Retinal changes accompanying  uncontrolled diabetes. Various stages present from background retinopathy to proliferative retinopathy. Uncontrolled diabetes can lead to retinal detachment and ultimately blindness.

Dilated pupil

Enlarged pupil. Occurs normally in dim illumination, or may be induced by certain legal or illegal drugs (mydriatics, cycloplegics).May also result as a consequence from ocular trauma or potentially serious neurological issues.


Unit of measurement  to designate a patient’s numerical prescription value.

Diplopia, double vision

Perceptually seeing more than one of the same image; may be noted horizontal, vertical or diagonal.


Tiny deposits on the retinal tissue.Common after age 60; if found in the macular area, may be an early sign of macular degeneration.

Dry eye syndrome

May be due to tear production and or quality deficiency.Occurs more often in women than men.Symptoms may cause foreign body sensation, burning eyes,  watering, grittiness, light sensitivity, and contact lens intolerance.


Outward turning of the upper or lower eyelid so that the lid margin does not rest against the eyeball.May lead to serious corneal exposure issues.Primarily etiology is aging.


The state in which no refractive error is found.ie: No eyeglass prescription needed.


Inward turning of upper or lower eyelid so that the lid margin and lashes  rests against and rubs the eyeball.

Esotropia, cross-eyes

Eye misalignment in which one or both eyes deviates inward.

Excimer laser

Class of lasers that removes corneal tissue accurately without heating it.Used for photorefractive keratectomy (PRK) and LASIK (laser in situ keratomileusis) proceedures.


Eye misalignment in which one or both eyes deviate outward (away from nose).

Extraocular muscles

Six muscles that move the eyeball (lateral rectus, medial rectus, superior oblique, inferior oblique, superior rectus, inferior rectus) through all cardinal positions.


Structures covering the front of the eye, which significantly help to protect it from debris or injury. Helps to distribute the tear film over the corneal surface.


A farsighted eye must use the focusing system to keep maintain clear distance vision and must expend even greater focusing effort to maintain clear close up vision


Vitreal gel changes located in the back of the that are described as spots, cobwebs, spider web, etc. Can present normally with aging or may be associated with a pending retinal tears or detachment, or internal inflammation.


Central area of the macula that produces the sharpest vision possible.


Most  posterior portion of the eyeball that contains the retina, optic nerve, macula,  and blood vessels.


Group of diseases characterized by increased intraocular pressure resulting in damage to the optic nerve and retinal nerve fibers.An insidious quiet eye disease that can  destroy your vision without symptoms until it is too late. May be treated well (NOT CURED) by prescription eye drops, minor laser procedures, or via filtration surgery.


Process of evaluating the anterior chamber angle through a gonio lens.


See Farsightedness.


Blood in the anterior chamber.May occur after blunt trauma, surgery, or infection.

Intraocular pressure

The normal occurring pressure that is measured  through a technique called tonometry.

IOL (intraocular lens)

Special polymer material that is surgically implanted in an eye replacing the eye’s natural lens that has become cloudy (cataract).


Pigmented tissue that color to the eye (e.g., blue eyes). Controls light entering the eye by varying the size of the pupil.


Degenerative corneal disease that can over time severly affect vision. Characterized by generalized thinning and a cone-shaped protrusion of the central cornea.Generally occurs in both eyes. Primary treatment custom rigid gas permeable contacts.

Lacrimal gland

Gland responsible for producing the aqueous portion of a tear.


Acronym: LAser in SItu Keratomileusis.Type of refractive surgery wherein the cornea is reshaped to change its optical power. Used for correcting myopia, hyperopia, and astigmatism.

Legal blindness

Best-corrected visual acuity of 20/200 or less, or reduction in visual field to 20o or less, in the better seeing eye.

Lens; Crystalline lens

The eye’s natural lens. Transparent, biconvex intraocular tissue that helps bring rays of light to a focus on the retina.

Low vision

Term usually used to indicate vision of less than 20/200.


Small central area of the retina surrounding the fovea.Anatomical structure responsible for sharp crisp vision.

Myopia, nearsightedness

Focusing defect in which the eye is overpowered. Specifically vision is naturally clear up close and blurry far away.


See myopia.


Abnormal formation of blood vessels within the eye. Can develop in patients with diabetes, wet macular degeneration, post-trauma, etc.

Non- contact tonometry (NCT)

Measures the amount of pressure inside one’s eye via an air puff.


Involuntary and rhythmic oscillating eye movements faster in one direction than the other.


(MD) specializing in surgery and problems related to eye from systemic and ocular diseases and disorders.

Optic disc, optic nerve head

The main nerve that enters the back of the eye.Brain tumors, glaucoma, and neurological disorders may be observed from changes to the optic nerve.


A non-doctor eye care professional who makes and adjusts eyeglass lenses from prescriptions supplied by an optometrist. Can become certified by The American Board of Opticianry reflecting special skills and knowledge.


Is a licensed Doctor of Optometry (OD) who specializes in diagnosing refractive errors and binocular vision problems and prescribe glasses and contact lenses. They also routinely diagnose, treat and manage eye disease, infection, and injuries.


Discipline dealing with the diagnosis and treatment of defective eye coordination, binocular vision, and functional amblyopia by non-medical and non-surgical methods, e.g., glasses, prisms, exercises.


Refers to testing the peripheral vision of an eye. Information obtained of a patient’s visual field can indicate glaucoma, neurological issues, pituitary tumors, brain injuries, etc.

Peripheral vision

The area of noticeable side vision in all meridians per eye.

Punctal plug

A small medical device made of silicone and or collagen that is painlessly inserted into the tear duct (puncta) of an eye to block the duct. Used in dry eye patients and sometimes as a proactive tool in LASIK patients.


The black circular opening in the center of the iris that regulates the amount of light that enters the eye.

Radial keratotomy (RK)

Series of spoke-like (radial) cuts made from the corneal periphery to correct nearsightedness and astigmatism.Common refractive procedure in the 1980’s-2000.


Test to determine an eye’s refractive error resulting in the best corrective lenses needed to sharpen vision.

Refractive error

An optical defect causing a blurred retinal image.Typically corrected by eyeglasses, contact lenses, or refractive surgery (LASIK, PRK).


The layer of highly sensitive visual tissue in the back of the eye. Equivalent to the film in a camera.

Retinal detachment

Separation of one or more layers of the retina tissue. Markedly disturbs vision if the detachment is located centrally. Most are asymptomatic and found during routine dilated retinal exam or viewing an Optomap® image. Generally  requires immediate surgical repair.


Opaque, fibrous, protective outer layer of the eye (“white of the eye”).

Secondary cataract

See after-cataract.

Slit lamp

 Specialized microscope used for examining the eye’s anatomy.

Snellen chart

Test chart used for assessing visual acuity. Contains rows of letters, numbers, or symbols in standardized graded sizes.


Eye misalignment caused by extraocular muscle imbalance.

Sty, stye

An acute pustular-like infection of the natural glands located in an eyelash follicle along the eyelid margin.


Measurement device used to ascertain the eye’s intraocular pressure.(see also non-contact tonometry).


Eyeglass lens that incorporates three specific visual areas of  clarity. The top portion is for distance vision(>20 ft.), the middle section is for the computer/dashboard distance, and the lower segment is designed for reading vision (~16 in.).


What is deemed as a normal visual acuity.

Visual acuity

Assessment of the eye’s ability to clearly distinguish details and shape of an object

Visual field

The cumulative side (peripheral) vision seen per eye. The loss of any portion of the peripheral vision, which is almost always unnoticed by the person, is a serious sign and can signify glaucoma, pituitary tumor, stroke, and or eurological diseases.

Vitreous, vitreous humor

Transparent, colorless gelatinous mass that fills the rear two-thirds of the eyeball, between the lens and the retina.

Vitreous detachment

Separation of vitreous gel from retinal surface. Usually innocuous, but may cause retinal tears, which could lead to retinal detachment. Frequently occurs with aging as the vitreous liquifies yet can be found in some disease states, e.g.diabetes and high myopia.

  • Catherine G.
    My family has been coming to this location for 3 years because of Dr. Ziskrout. He is extremely personable and intelligent. His exams are like talking with an old friend. And if you are not a fan of eye exams, this is the office to come to because they make you feel at ease the entire time. Carlos is also very good at his job. Finding you the best glasses and getting all of the insurance information together so you know your budget. I love that this office texts appointment reminders and when glasses are ready for pick up. They are a well run office and it shows. Thank you Eye Trends Barker Cypress!
    Catherine G.
  • John P.
    Great staff resulting in outstanding service. Carlos is outstanding. Dr Pham is very thorough and explains things in laymen’s terms.
    John P.
  • Paula L.
    I have been coming here for years. This was my first visit with Dr Ziskrout. He is wonderful! He listened carefully to my concerns. Found a solution and now I’m seeing really well. Definitely 5 star.
    Paula L.
  • Hector V.
    Great experience, friendly and courteous staff. Dr Pham was very clear and patient dealing with my high sensitivity to light. My allergies irritate my eyes and my blurred vision was restored in a few days. His experienced staff conducted all types of tests in office. It’s location , makes it very convenient to access from any point. A great experience and a nice Dr.
    Hector V.
  • James M.
    As always, Doctor Huy “Tommy” Nguyen hit another home run in my book. Dr. Nguyen really cares about me as a patient and and I’m comfortable with his diagnosis. The entire staff are just wonderful people. They’re friendly, courteous, intellectual and sincerely genuine. From start to finish, it’s a pleasure having to visit Dr. Nguyen’s office. Don’t take my word folks! The next time you need to see an eye doctor; schedule an appointment with Dr. Huy “Tommy” Nguyen and you’ll understand what I mean.
    James M.
  • Arlene S.
    I’ve had a lot of trouble over past years with my eyes (went to neuro-opthamologist for 30 years) & moved here a few years ago. After disaster with a neuro-opthamologist here, I found Dr Z who is fantastic! He has enabled me to see better than I have in 30 years without pain! He & optometrist Julie showed tremendous, sensitivity, understanding & patience for which I am most grateful. I now have new light-weight style frames & lenses that are very comfortable & flattering to my small face... & I can see!!
    Arlene S.
  • Shelly W.
    I have been very happy with the people who work at Eye Trends Barker Cypress for many years now. Dr. Pham is so friendly and fun. It is obvious, to me, that she loves what she does, which makes for a great doctor/patient relationship. Carlos was very attentive, knowledgeable, helpful, and patient with me as I took time to find a new pair of glasses. I never felt rushed and he was great at helping me to make a decision that I know that I will be happy with. I highly recommend Eye Trends in Cypress. If you are in need of a place for optic care, this is the place to go!
    Shelly W.
  • Sam U.
    I was and still amazed at how 2racious and attentive the doctors and staff were on my recent visit for an eye exam and ew glasses. I could not be more happy I the care and respect that was shown. These people really care about you. Thank you so much. I highly recommend.
    Sam U.
  • Katie T.
    My whole family has been going for years. I’ve never even thought about going somewhere else! Each appointment I’ve had is always quick and easy. I’ve never had to wait for a long time and always get quality care by workers who care about their job.
    Katie T.
  • Colleen G.
    Dr. Katie Pham and the entire Eye Trends Barker Cypress team were courteous and helpful at my visit. I appreciate the time they all took, never making me feel rushed. Love this place!
    Colleen G.
  • Mark O.
    Been coming to Eye Trends Barker Cypress for the past 5 years. Small and cute/clean place that gets you in and out super fast. All employees and doctors know what they’re doing and are very friendly.
    Mark O.