Vision Screening

What is Vision Screening?

Vision screening is a process of testing the sight of children or adults to check whether they have any vision problems or not. It is also known as vision testing or vision evaluation. It is usually used to detect vision problems early, so that a person can take the necessary action to improve their vision. It is an important part of a comprehensive eye exam.

Preparation for Vision Screening

Preparation for vision screening is important for accurate, efficient results. It consists of basic instructions to ensure the best results. For children, it is recommended that they avoid overexposure to bright light, like sunlight, for a few hours before the test. Older adults and adults who require more detailed testing may need a longer preparation time.

  • Avoid bright light for at least a couple of hours before the test.
  • Sleep well the night before the test.
  • Follow all instructions given by the optometrist.
  • If wearing contacts, make sure to remove them at least 45 minutes before the test.
  • Make sure to keep any corrective eyeglasses with you on the day of the exam.
  • To help with dilation, bring sunglasses and prepare for the possibility of blurred vision.

Procedure of Vision Screening

A vision screening is quick and easy and typically takes around 15 minutes to complete. The procedure may include:

  • Assessing the patient’s visual acuity with an eye chart.
  • Focusing sharply on objects at different distances to measure refractive errors.
  • Measuring the curvature and size of the eye to detect any abnormalities.
  • Using special charts or tools for kids who cannot answer questions.
  • Checking color vision.
  • Evaluating the eyes’ movements and response to light.

Types of Vision Screening

The type of screening that is performed depends on the age, eye condition, and special needs of the patient. Vision screening for children is especially important, as this can help identify vision problems early, and prompt parents to arrange for a more comprehensive eye exam.

  • Retinoscopy: Retinoscopy is a process used to measure the refraction of light in the eye and detect any refractive errors. It is generally performed on young children or those with motor challenges, making it difficult to answer questions.
  • Autorefractors: Autorefractors assess the eye’s refractive errors and power measurements. It is a quick and accurate way to measure refraction. However, it cannot detect conditions like cataracts or glaucoma.
  • Snellen Eye Charts: Snellen eye charts are used to measure visual acuity. This helps determine if a person has an uncorrected refractive error. Eye doctors can also measure the peripheral visual field with a devices, such as an Amsler grid.
  • Special Eyecare Tests: Special tests, such as Lanthony desaturated D-15 color perception test, can be used to detect any eye color perception problems. The Shinobu Ishihara test is often used to identify color deficiency.
  • Stereopsis Test: The stereopsis test measures the patient’s depth perception strength. It is usually done using a special chart.

Risks Associated with Vision Screening

Vision screening is generally a safe and simple procedure. However, the results may by misleading in some cases, giving false positives or false negatives. Also, vision screening may miss or overlook certain eye conditions, such as glaucoma. Therefore, it is important to follow up any results that suggest difficulties with a comprehensive eye exam.

Why is Vision Screening Important?

Vision screening is important in order to prevent vision problems from becoming worse, and to raise awareness of the importance of regular eye exams. Eye conditions like glaucoma may not have any symptoms in the early stages, so regular vision screenings can help detect them before they become too serious. Furthermore, vision screening may be used to detect refractive errors, which can be corrected with eyeglasses or contact lenses.

When to Get Vision Screening?

The American Academy of Ophthalmology recommends that children should have their first eye exam before they are age three. This is followed by regular eye exams for children until they reach the age of 18. Children with special needs require more frequent eye exams, starting from the time they are an infant. Adults 19-39 years of age should get a comprehensive eye examination every two to three years, while adults 40 and above should have one every one to two years. If you notice any changes in your vision, it is best to contact your eye care doctor right away for a comprehensive eye exam.