A routine vision exam focuses on vision and measuring a prescription for glasses if needed. During this exam, several screening tests are performed to rule out medical causes of decreased vision. If a medical problem is found during this screening, a more comprehensive medical evaluation may be recommended.
TESTS PERFORMED DURING A ROUTINE VISION EXAM AT TOTAL VISION CARE (TVC):
Auto-refraction- an automated measurement of the focusing system in the eye. This gives a starting point for the doctor to measure a glasses prescription.
This is especially helpful for examination of children and non-verbal patients as it can give a very close approximation of a glasses prescription.
Lensometry- this allows the technician to read the power in your current glasses. It's helpful for the doctor to know what power your eyes are accustomed to seeing through. If large changes are made the doctor will discuss how to adapt to the changes in your glasses.
*Bring your glasses to your appointment so we can use lensometry to compare your current glasses to our new measurements. We will show you the difference and discuss whether or not this change is significant enough to warrant buying new glasses.
Visual Acuity- you will be asked to read a vision chart at 20 feet and at 14-16 inches to measure distance and near vision in each eye.
- NOTE: Please inform the technician if the patient is unable to read or accurately verbalize what they are seeing. We have alternate methods for checking vision that allow us to examine young children and patients with special needs.
- If you wear your glasses full-time, we do not always measure your vision uncorrected, unless you wear your glasses part-time. We will check your vision with and without your glasses to discuss what viewing situations your glasses may be beneficial or required.
General screening- a technician/clinic assistant will perform some basic pre-screening tests to determine how your eyes function:
- Extra-ocular motilities (EOMs)- measure how well your eyes look side to side and up and down. Some neurological conditions can limit the ability of the eyes to move together in all directions. This can cause double vision and reduced side vision.
- Convergence- this is the ability of the eyes to cross or turn inward when viewing a near target. This skill is important for reading. Double vision, blurry vision, words moving on the page, reversals of letters/words, loss of place on the page, reduced attention span, and slow reading skills can be signs of poor convergence. This is a very easy skill to train with some basic exercises prescribed for home therapy.
- Accommodation- this is the ability of the eyes to focus from far to near. When the eyes look at a distance, the lens in the eye should be relaxed. When the eyes shift to focus up close, the lens shifts to bring the near target into focus. Reduced focusing abilities for near work can cause issues with reading. Blurred vision, loss of place when reading, reversals, slow reading skills, loss of attention when reading, avoidance of near work can all be signs of accommodative insufficiency. If this is not treated at a young age, kids can develop a low self esteem in school and believe that they are just not good readers.
- Peripheral (side) vision is the ability to notice moving objects outside of your central vision. The peripheral retina sees movement even in low light situations. If peripheral vision is reduced, this can be a sign of something affecting the health of the retina or the nerve pathways to the brain including a stroke or retinal detachment.
- Pupil responses are tested to ensure the optic nerve is receiving light and sending that information to the brain and back to the eye to tell the pupil to constrict. If the pupils are not reacting normally, this can be a sign of certain neurological problems that need to be addressed.
These screening tests help to find any neurological problems or muscle/focusing imbalances that can affect vision, learning, and eye health. Once these screening tests are completed, the doctor or clinic assistant will move on to the main reason you came in for your routine vision exam:
Refraction- this is the measurement of a glasses prescription. We use a "phoroptor" to show you different lenses and find the lens combination that clears your vision for all distances. A digital phoroptor is the newest method for this measurement and allows for more efficient methods to find the best prescription for your eyes.
- NOTE: if a patient is non-responsive or unable to accurately state which lens option is clearer, the doctor has alternate methods to acquire a prescription for glasses. Dr. Mayes is able to perform this test on young children and patients with special needs that may not be able to verbalize what they are seeing.
- Tonometry- this is the measurement of intra-ocular pressure (IOP). The eye is like a water balloon it is full of fluid and is constantly making new fluid and absorbing old fluid to maintain good eye health. If the IOP is too high for the health of the eye, damage to the optic nerve can cause gradual loss of peripheral (side) vision and eventual blindness. This process is painless and has no symptoms until it has become severe. For this reason, IOP is measured at every vision exam. If IOP is elevated, you will be asked to return for more testing to determine the cause and if any treatment is necessary.
- Tonometry can be performed by several methods:
- Some offices use the "puff of air" method (we do not use this due to inaccuracy and patient complaints).
- Tonopen- this is a hand held tool that allows the technician to check the IOP. Some tonopens require the eye to be numbed with anesthetic eye drops. **At TVC, we use the i-CARE tonopen which allows for the technician to check IOP without having to instill any anesthetic drops. This method is tolerated very well by patients of all ages including young children.
- Goldmann Tonometry- this method is considered the "gold standard" because it is the most accurate method for measuring IOP. The i-CARE has been shown to be a very accurate screening tool, however the Goldmann is used to verify any readings out of the normal range.
- Tonometry readings only give us the IOP for that moment. Your IOP can fluctuate from day to day. We recommend regular eye exams for all patients including tonometry readings in order to build a history of your IOP readings. If you transfer your care to another doctor, we recommend you have your records transferred in order to continue building a history of your IOP. This allows your eye doctor to diagnose problems earlier and reduce your risk of vision loss.
- Tonometry can be performed by several methods:
- Slit Lamp Examination- The "slit lamp" is a microscope that allows the doctor to view the eye under high magnification.
- Screening of the front part of the eye: the lids, lashes, cornea, conjunctiva, anterior chamber, iris, and lens can all be viewed with ease.
- Screening of the back part of the eye: a magnifying lens can be held in front of the eye to allow the focus to extend to the back of the eye and the doctor can view the optic nerve, macula, retina, and blood vessels in the retina.
- Flourescein dye drops can be instilled to temporarily stain the tears. A blue light is used with the slit lamp allowing the doctor to evaluate signs of dry eyes, infection, or injury to the front surface of the eye.
- Dilated Examination- Dilating drops can be instilled to cause the pupils to stay dilated and to stop the eye from focusing. Side effects of the dilating drops are light sensitivity and blurry vision (especially at near viewing).
- Dilation allows the doctor to use bright lights and magnifying lenses to get a wider view in the back of the eye and view out further into the periphery of the retina. This is not a requirement of a routine vision exam, but it can be done for a more detailed eye health screening.
- Dilation allows the doctor to re-measure a glasses prescription while the eyes can not focus. This ensures the correct measurement was attained. This is done for young children, patients with special needs, and those who are far-sighted (hyperopia) if there are concerns that the initial measurement may not be accurate.
- NOTE: At TVC, if the doctor feels dilation is necessary to acquire the measurement for glasses, this will be discussed before the drops are used. A dilated exam for eye health screening during a routine vision exam is not always necessary, therefore patients are always given the opportunity to decline dilation.
- Glasses Prescription- Dr. Mayes prescribes glasses for all your needs including:
- Single Vision glasses for driving, computer, reading, or general purpose.
- Bifocal, trifocal, or Progressives for patients needing a different power to focus at different ranges.
- Dr. Mayes will discuss your vision complaints, your daily tasks, and personal preferences.
- Every patient has different needs and finding the right solution for each patient is a priority for ensuring satisfaction.
- Specialty prescriptions: sports glasses, shooting/hunting glasses, low vision, prism to reduce double vision or eye strain. Please inform Dr. Mayes of any specific needs you may have for specialty correction.
- Recommendations for specific tints and coatings that meet your unique vision challenges.