What is the difference between short and long sightedness?
Short sightedness blurs distance because focus falls in front of the retina, long sightedness blurs near focus for most of the day because it falls behind, and astigmatism blurs in a direction because the cornea is curved unevenly. More than one can be present at once.
- Subject
- Vision problems
- Topic
- Blur, night vision & strain
- Kind of question
- What is…
- Last reviewed
- 22 September 2026
What this answer depends on
- Which distances are affected
- Whether the blur is the same in every direction
- Whether the two eyes measure similarly
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Where this answer sits
It is one of 483 answers in the vision and eye health knowledge base, filed under Vision problems & prescriptions in Blur, night vision & strain . 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.
- Comparison LASIK vs SMILE
- Comparison LASIK vs PRK
- Comparison SMILE vs PRK
- Comparison SMILE Pro vs LASIK
- Condition Myopia (short 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