Strabismus is diagnosing through a comprehensive eye exam. Testing for strabismus, with special emphasis on how the eyes focus and move, may include:
Strabismus diagnosis test
- Patient History – Need a patient history to determine any symptoms the patient is experiencing, presence of any general health problems, medications taken, or environmental factors that may be contributing to the symptoms.
- Visual Acuity - Visual acuity measurements are taking to assess the extent to which the vision may be affected. As part of the testing, patients will ask to read letters on specific distance and near reading charts. This test measures visual acuity, which is writing as a fraction such as 20/40. When testing distance vision, the top number is the standard distance at which testing is performing, twenty feet. The bottom number is the smallest letter-size that can read at the twenty-foot distance. A person with 20/40 visual acuity would have to get within 20 feet of a letter that should see at forty feet in order to see it clearly. Normal distance visual acuity is 20/20.
- Refraction - it is conduct to determine the appropriate lens power needed to compensate for any refractive error (nearsightedness, farsightedness, or astigmatism). Using an instrument called a phoropter, the optometrist places a series of lenses in front of the eyes, and measures how they focus light using a hand held lighted instrument called a retinoscope. Alternatively, the doctor may choose to use an automated instrument that automatically evaluates the refractive power of the eye. The power is then refining by the patient's responses to determine the lenses that allow the clearest vision.
- Alignment and Focusing Testing - How well the eyes focus, move and work together needs to assess. In order to obtain a clear, single image of what is being viewing, the eyes must effectively change focus, move, and work in unison. This testing will look for problems that keep the eyes from focusing effectively or make it difficult to use both eyes together.
- Examination of eye health - The structure of the eye is observing to rule out any eye disease that may be contributing to strabismus. The health of the external and internal parts of the eye will assess using various testing procedures.
This testing may be without the use of eye drops to determine how the eyes respond under normal seeing conditions. In some cases, such as for patients who cannot respond verbally or when some of the eyes focusing power may hide; eye drops may be used. They temporarily keep the eyes from changing focus while doing this test.
Using the information obtained from these tests, along with results of other tests, the optometrist can determine if one have strabismus. Once testing is complete, the optometrist can discuss options for treatment.