Two eyes, aimed and focused as one.
When you look at something close, two controls work together. The eyes turn inward to aim, and the lens inside each eye changes shape to focus. When either one falls short, close work gets hard.
- Aiming
- Convergence: both eyes turn in
- Focusing
- Accommodation: the lens thickens
- Reading at
- About 40 cm
- Common signs
- Eyestrain, headaches, words that blur, double or move
Who it helps
Children who avoid reading
Losing their place, skipping lines, or rubbing their eyes during homework.
Adults with screen strain
Tired eyes or headaches after close work, even with up-to-date glasses.
Double or moving words
Print that drifts, doubles or swims on the page after a few minutes.
How the two controls work
Top view, five stepsLook far.
Eyes and distances not to scale. Values for a 62 mm pupil distance.
What the assessment involves
Sequence / 04History
Your symptoms, when they start, and how long you can read comfortably.
Measurement
How close the eyes can turn in, how far each can focus, and how they hold alignment.
Diagnosis
Which control is falling short: aiming, focusing, or the link between them.
Plan
Reading glasses, prism or eye exercises, reviewed until the symptoms settle.