Retinoscopy Tips: With vs Against Movement and Working Distance
Last updated: October 2026
Short answer: in retinoscopy, a "with" movement means you add plus lenses and an "against" movement means you add minus, until the reflex fills the pupil with no movement (neutrality). Then subtract your working distance: 1.50 D at 67 cm or 2.00 D at 50 cm. Find and neutralise each of the two principal meridians separately to measure astigmatism.
The basic rules
| What you see | Meaning | What to do |
|---|---|---|
| "With" movement (reflex moves the same way as the streak) | Far point is behind you (relatively hyperopic) | Add plus |
| "Against" movement (reflex moves the opposite way) | Far point is between you and the eye (myopic beyond your working distance) | Add minus |
| No movement, pupil fills with light | Neutrality | Record the lens, then subtract the working distance |
Working distance correction
- Working distance lens = 1 ÷ working distance in metres.
- 67 cm → 1.50 D; 50 cm → 2.00 D.
- Example: neutralised with +3.00 D at 67 cm → prescription = +3.00 − 1.50 = +1.50 D.
- Measure your own working distance (arm length) once, and use it consistently.
Reading the reflex
- Far from neutral: the reflex is dim, narrow and moves slowly.
- Near neutral: the reflex becomes bright, wide and fast.
- Bracket neutrality: go just past it (a small reversal in movement) and come back, so you know you are truly there.
Finding astigmatism
- Rotate the streak through 360°. In astigmatism, look for the four clues:
- Break: the reflex inside the pupil is not aligned with the streak outside it
- Width: the reflex is thinnest when aligned with a principal meridian
- Intensity: the reflex is brightest when aligned
- Skew: the reflex moves obliquely when the streak is off-axis
- Align the streak with each principal meridian and neutralise each separately.
- The difference between the two meridians gives the cylinder; the meridian you neutralise with the more plus lens gives the sphere in a minus-cylinder prescription.
Common pitfalls
- Accommodation in children and young adults: use cycloplegia (for example, cyclopentolate) for accurate results in children.
- Off-axis viewing: stay as close to the patient's visual axis as possible, while the patient fixes on a distant target.
- Scissors reflex (two bands moving in opposite directions) suggests irregular astigmatism, such as keratoconus.
- Dim reflex from media opacity (cataract) or very high refractive errors; try high-power lenses to find movement.
Frequently asked questions
What does "with" movement mean in retinoscopy?
The reflex moves in the same direction as the streak. It means the eye is relatively hyperopic for your working distance, so you add plus lenses.
How much do you subtract for working distance?
One divided by the working distance in metres: 1.50 D at 67 cm or 2.00 D at 50 cm.
What is a scissors reflex?
Two light bands moving in opposite directions within the pupil. It suggests irregular astigmatism, classically keratoconus.
Related: Jackson cross-cylinder, duochrome test and optics lectures.
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