How is long sightedness measured?
By refraction: a test that finds the lens power that gives you the clearest vision, expressed as a prescription with a plus sign for long sightedness. In younger patients the measurement is usually repeated after drops that relax the focusing muscle, because otherwise the eye hides part of the prescription.
- Subject
- Vision problems
- Topic
- Hyperopia (long sightedness)
- Kind of question
- Other questions
- Last reviewed
- 22 September 2026
In more detail
The drops matter more in this prescription than in short sightedness. A long sighted eye compensates by focusing harder, and a refraction taken without relaxing that effort can understate the true figure, which is the figure surgery would be planned from.
What this answer depends on
- Whether the measurement was taken with the eye relaxed
- Whether a topography scan was also taken
- How consistent the readings are between visits
Related guides
People also ask
The questions readers move to next from this one: the closest subjects first, from either question bank.
Where this answer sits
It is one of 483 answers in the vision and eye health knowledge base, filed under Vision problems & prescriptions in Hyperopia (long sightedness) . The subject page carries the answers either side of it, and the hub is searchable.
Subjects this question touches
The pages that answer the subject behind the question, rather than the question itself.
- Place Eye tests in Dubai
- Condition Hyperopia (long sightedness)
This information is for educational purposes and does not replace an examination by a qualified eye-care professional.
General answers cannot tell you what is happening in your own eyes. Only an examination by a qualified ophthalmologist can do that.
Sources & further reading
We prefer primary sources. Where a claim comes from a manufacturer, a single study or a regulator, it is labelled as such below.
- EyeSmart: eye health information for the public
Patient-facing material from the largest ophthalmology professional body, covering conditions, tests and treatments outside refractive surgery.
Used for Cross-checking patient-facing explanations of non-refractive eye conditions; Describing what tests such as dilation and OCT involve.
Link checked 23 September 2026