Eye Conditions and Refractive Errors
Independent Clinic verification in progress Medical review pending Updated
The conditions behind the symptoms people search for, and the refractive errors laser surgery is meant to correct.
Quick answer
An eye condition is what is happening to the eye; a refractive error is how well it focuses light. Short sight, long sight and astigmatism are refractive errors, and conditions such as cataract, glaucoma and keratoconus are structural. Some of them change whether refractive surgery is appropriate.
These pages describe conditions in general. They cannot tell you what is happening in your own eye, and several of the conditions listed here are detected only during a dilated examination.
- Pages in this family
- 11
- Guides covering them
- 12
- Questions linked
- 8
11 pages in this family
- Myopia (short sightedness)
The eye focuses light in front of the retina, so near objects are clear and distant ones are blurred. It is the refractive error most commonly treated with laser vision correction.
- Hyperopia (long sightedness)
The eye focuses light behind the retina. Younger eyes often compensate without noticing, which is why it tends to present later than short sightedness and is assessed more cautiously for surgery.
- Astigmatism
The cornea is curved unevenly, so light is focused differently across different axes and the blur is not the same in every direction. It commonly occurs alongside short or long sightedness.
- Presbyopia
The lens of the eye hardens with age, making it harder to focus on close objects. A natural part of aging, typically beginning after age 40.
- Dry eye
The eye does not produce enough tears, or the tears evaporate too quickly, leading to discomfort, blurred vision and sensitivity to light. Common with screen use and aging.
- Cataract
The lens of the eye becomes cloudy, causing blurred, dimmed vision and increased glare. Common with aging and treatable with surgery.
- Glaucoma
Increased eye pressure that can damage the optic nerve, often without noticeable symptoms early on. Requires regular eye pressure testing.
- Keratoconus
The cornea thins and bulges into a cone shape, causing distorted vision and increased sensitivity to light. Usually begins in teenage years or early adulthood.
- Retina and macula conditions
Conditions affecting the retina and macula, the light-sensitive tissue at the back of the eye. Includes macular degeneration and retinal detachment.
- Diabetic eye disease
Eye problems caused by diabetes, including diabetic retinopathy and macular edema. A leading cause of vision loss in adults.
- Eye infections, allergies and injuries
Infections and inflammatory conditions affecting the eye surface and surrounding tissues, including conjunctivitis and eye injuries.
Subject pages in the knowledge base
- Eye conditions & diseases
Dry eye, cataract, glaucoma, keratoconus, retinal and diabetic eye disease explained: what each condition is, how it is diagnosed, and why some of them change which vision correction options are open to you.
- Vision problems & prescriptions
Short sightedness, long sightedness, astigmatism and presbyopia explained in plain language, including why each one happens, how it is measured, and which of them laser vision correction can and cannot change.
Questions answered on these subjects
Guides that cover these subjects
- The eye examination before surgery
What each test measures, and why a refraction on its own is not enough.
- Am I a candidate for SMILE Pro?
The factors an assessment settles, and why no page can decide suitability for a particular eye.
- Risks and side effects
A balanced account of what can go wrong, from the common and temporary to the rare and serious.
- The vision knowledge base
Every question the site answers about eyes and vision, grouped by subject, with a search box.
- PRESBYOND Laser Blended Vision
What the treatment is, how the two-eye plan works, what it can and cannot deliver, and where every part of it is explained in full.
- Who is a candidate for PRESBYOND
The measurements, history and expectations that decide whether a blended vision plan is reasonable for a particular pair of eyes.
- PRESBYOND compared with monovision LASIK
Two ways of planning a difference between the eyes, compared on the optical strategy, the size of the difference and the trade-offs each accepts.
- PRESBYOND side effects and risks
The side effects of a corneal laser procedure, plus the specific risk of a planned difference between the eyes.
- PRESBYOND recovery and adaptation
Healing, adaptation, follow-up and the everyday decisions that belong to the treating surgeon rather than to a web page.
- PRESBYOND results and durability
What the published studies measured, what they reported, and why a cohort result cannot predict one person’s outcome.
- PRESBYOND cost in Dubai and the UAE
Why this site publishes no PRESBYOND price for the UAE, and the quote questions that make two clinics comparable.
- Alternatives to PRESBYOND
Glasses, contact lenses, monovision and lens surgery, compared on what each can change and what each costs you in trade-offs.
Rare inherited retinal dystrophies, paediatric syndromes and neuro-ophthalmological conditions are outside the coverage of these pages. Where a symptom can be caused by something serious that is not covered here, the page says so and sends you to urgent care instead.
These pages describe subjects, not people. Nothing here is a diagnosis, and none of it replaces an examination by a qualified ophthalmologist.