Optometry
Optometrists are primary care eye doctors that are trained to provide the best standards of comprehensive eye care, ranging from an assessment and review of overall eye health and visual function, to informing a prescription for vision correction, to referring for secondary treatment by an ophthalmologist.
Ophthalmologists are medical doctors who have completed specialized residency training in the study, diagnosis, and treatment of eye disease. They are secondary-level health care providers and they usually use drugs and/or surgery for treatment. A person that requires ophthalmological care (to obtain cataract surgery, for example) usually require a referral from the optometrist or family doctor.
Opticians are technicians trained through a college program to fabricate and fit vision aids based on prescriptions from optometrists, ophthalmologists and physicians. Opticians are licensed to provide spectacles, and they may also dispense contact lenses and other optical aids. They do not assess, diagnose, or treat eye conditions, nor do they write out prescriptions for eyeglasses or contact lenses.
Eye Examinations
An eye exam is more than just an eye chart - it is a complete, comprehensive exam and detailed examination of your visual ability, vision and eye health. This examination is defined in regulation under Ontario's Health Insurance Act as:
- Relevant History (ocular medical history, past medical history, family history)In this step, your optometrist will assess your past and current medical history, and the medical history within your family, in order to determine your risk factors for certain eye health conditions and overall health conditions that may affect your eyes. Your ocular history - incidences of eye conditions, prescriptions, eyewear, work with any other eye doctors, etc - will also be assessed.
- Visual Acuity ExaminationAs a baseline, your optometrist will examine your visual acuity by means of an eye chart. The placement, sizing and gradations on a standardized eye chart will help your optometrist gauge your current visual acuity (the clearness of your vision) for far near and distances.
- Ocular Motility ExaminationIn order to determine how well your eyes and visual system function in terms of movement, reflexes and tracking, your optometrist will conduct a number of tests to determine if there are any underlying problems. Any problems found in your eye movement or binocular vision may require treatment, or could be symptomatic of other physiological or neurological disorders.
- RefractionAs part of this step, a phoropter can be used to determine amount of refractive error which is needed to create a prescription for eyeglasses if one is needed. A series of lenses and settings are used to assess the refractive error of your vision and define any corrective prescription.
- Slit Lamp Examination of the Anterior Segment (Biomicroscopy)A slit lamp is used to shine a light into the eye to facilitate an examination of the anterior segment of the human eye - including the conjunctiva, iris, natural crystalline lens and the cornea. The binocular slit-lamp examination provides a stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions.
- Ophthalmoscopy (Direct, Binocular Indirect, or Monocular Indirect Ophthalmoscope or Non Contact Fundus Lens)Ophthalmoscopy is a test that allows your optometrist to see inside the fundus of the eye and other structures (including the retina, optic disc, macula and fovea). This is conducted to help detect eye conditions such as retinal detachment, diabetes, macula degeneration or glaucoma.
- Advice & Instruction for the PatientPending your individual needs for care and follow-up, your optometrist will provide advice and/or referrals on a case by case basis. At this time, your optometrist will also advise you on how often to return for an eye exam.
- Additional Testing that Maybe Recommended/NeededAnd if required in accordance with generally accepted professional standards, any or all of the following elements may be included in the eye exam:
- Tonometry is conducted by your optometrist in order to determine the intraocular pressure, the fluid pressure inside the eye. It is an important test in the evaluation of patients with glaucoma and to assess risk factors for glaucoma.
- Digital Retinal Photography is done with a specialized instrument that takes a high resolution, digital image of the retina, the light sensing tissue at the back of the eye. This new technology is an important tool for helping the optometrist screen for and monitor, many different eye diseases such as glaucoma, macular degeneration, and diabetes.
- Dilated Fundus Examination is similar to the fundus examination mentioned above, but with the pupils dilated with drops to enhance what your optometrist can see during the examination.
- Visual Field examination by Confrontation Field is a visual field examination is used to detect and measure visual field loss. Visual field loss is the condition of having lost degrees of peripheral vision as a result of one or more eye health conditions. Such conditions may be of the eye alone, of the optic nerve or of the brain. Your optometrist can help determine causal factors in any visual field loss and implement a referral if needed.
- Visual Field Examination by Automated Visual Field Analyzer is a specialized piece of equipment designed for the early detection and monitoring of many different neurological disorders of the eye including glaucoma, multiple sclerosis and even tumours. A Humphrey Field Analyzer has a concave dome with a central fixation target. Generally, only one eye is tested at a time. The patient rests their chin in front of the dome and asked to focus on the center fixation light. The computer will shine lights inside the dome and the patient clicks the button whenever a light is seen. The computer then automatically maps and calculates the patient's full visual field to help the optometrist interpret the results.
- Corneal Topography is a specialized instrument used to give a detailed 3D map of the outer surface of the eye and is important in the diagnosis and monitoring of many different corneal diseases such as keratoconus, pellucid marginal degeneration and keratoglobus. Topography is used for complex astigmatic, keratoconic and orthokeratology contact lens fits. It is also very important in the pre- and post-operative care for laser eye surgery patients.
- Corneal Pachymetry is the measurement of the thickness of the cornea with a specialized ultrasound. It has many applications such as screening LASIK patients and detecting patients at risk of glaucoma.
Medical Conditions
The most damaging eye condition caused by diabetes is diabetic retinopathy. The incidence of retinopathy increases the longer someone has diabetes. Diabetic retinopathy causes the blood vessels of the retina (inner layer of the back of the eye) to leak, swell or develop abnormally which causes damage to the retina. This can result in vision loss that can range from mild to severe.
Very often people with diabetes don't even know they have diabetic retinopathy until significant damage to the retina has already happened. Prevention of diabetic retinopathy is best accomplished by maintaining normal blood glucose levels, blood pressure and blood lipid levels. A regular eye exam (minimum once a year) by an optometrist or ophthalmologist is essential to catch retinal changes as early as possible.
Nutrition
Here are six important nutrients for vision health:
- Vitamin C because it helps the body absorb iron, which ocular blood vessels and other eye cells need. Citrus fruits, bananas, apples, kiwis, peaches, tomatoes, broccoli and spinach are good sources.
- Vitamin D to help maintain calcium and phosphorus levels (milk, fish, eggs).
- Vitamin E is good for cell membranes and DNA repair (salads, wheat germ, nuts, peanuts, sunflower seeds, sweetpotatoes).
- Omega-3, DHA and EPA essential fatty acids are good for overall health (fish).
- Lutein and zeaxanthin are antioxidants that help the eyes absorb UV and blue light (leafy green vegetables,corn, green peas, eggs).
- Zinc helps move Vitamin A to the retina to help protect eye pigment. Low zinc levels are associated with cataracts and poor night vision (red meat, seafood, poultry and eggs, wheat germ, tofu).
Children’s Vision
Orthokeratology
After the completion of the initial consultation appointment, a typical treatment schedule involves a series of visits as follows:
- Lens pick-up (1 – 1½ hours)
- Next day (30 – 45 minutes) early morning
- 1 week (30 – 45 minutes)
- 2 weeks (30 – 45 minutes)
- 6 weeks (30 – 45 minutes)
- 6 months (30 – 45 minutes)
- 1 year (30 – 45 minutes)
Vision Therapy
The visual system accounts for over 70% of sensory information that is absorbed; thus, it is not surprising that vision plays a critical role in learning and a child's performance at school. Even though children do account for the majority of vision therapy participants, vision therapy can be beneficial for individuals of any age. Vision therapy has been used to help computer users reduce eyestrain, professional athletes improve hand-eye coordination, and head trauma/stroke patients whose vision is affected.
There is a common myth that having "20/20" eyesight constitutes perfect vision; however, an individual can have good vision but have deficits in their eye-teaming, eye-focusing, and eye-movement abilities.
Vision therapy works to improve conditions such as:
- Oculomotor disorders (inability to quickly and accurately move eyes)
- Non-strabismic binocular disorders (inefficient eye teaming)
- Strabismus (misalignment of the eyes)
- Amblyopia (poorly developed vision)
- Accommodative disorders (inability for the eyes to sustain focus for long periods of time when doing near work, and change focus from distant to near objects)
- Visual information processing disorders
The optometrist guides the patient through a series of procedures that are tailored to each individual. In order to promote the use of these abilities in everyday life, gross and fine motor training are often incorporated. The various vision exercises are completed by using lenses, prisms, filters, patches, and other materials and equipment.
Vision therapy involves weekly in-office sessions along with home activities which usually take between 15 – 30 minutes and should be done 4 – 5 times a week. Vision therapy can take anywhere from 6 weeks to a year or more before treatment is complete. Most problems can be significantly improved over 10 – 15 weeks, but certain dysfunctions, such as strabismus, usually take the longest. An average vision therapy length at most clinics is 4 – 6 months. Once vision therapy has been completed, the skills that are learned usually remain throughout life!
A binocular vision disorder can cause a number of symptoms including (but not limited to):
- Double vision
- Frequent headaches or eye strain
- Avoidance of reading or close work
- Blurred distance or near vision, particularly after reading
- Difficulty following a moving target
- An eye turning in, out, up, or down
- Tendency to close one eye
- Loss of place when reading
The following websites offer a wealth of information on vision therapy: