[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Ophthalmology](https://durgical.com/en/ophthalmology/) › [Refraction and vision](https://durgical.com/en/ophthalmology/areas/refraction/) › Contact lenses: types and complications

# Contact lenses: types and complications

- Topic

Contact lenses correct vision well but carry a small risk of serious corneal infection. Most problems come from sleeping in them or poor hygiene.

Updated Nov 5, 2026

**See it in 3D:** [Cornea](https://durgical.com/en/anatomy/cornea/)

## Key points

- Sleeping in lenses = main risk of keratitis.
- No tap water: Acanthamoeba.
- Red painful eye in a lens wearer = same day.
- Rigid lenses for keratoconus.

## What it is

Contact lenses sit on the tear film over the cornea. Soft lenses are the most common; rigid gas-permeable lenses correct irregular corneas (keratoconus) and high astigmatism; scleral lenses rest on the sclera; orthokeratology lenses are worn at night to reshape the cornea. Bandage lenses protect a healing cornea. Their main risk is microbial keratitis, which is much more likely with overnight wear and poor hygiene.

## Key facts

- Microbial keratitis: Pseudomonas and Acanthamoeba are the classic organisms.
- Overnight wear multiplies the risk of infection.
- Tap water, swimming and homemade solutions expose the lens to Acanthamoeba.
- Other problems: dry eye, giant papillary conjunctivitis, corneal new vessels from low oxygen, a tight lens.

## In clinical practice

- A painful red eye in a lens wearer is keratitis until proven otherwise: remove the lens and refer the same day.
- Colombian guideline: contact lenses can be used in children with errors of 4 dioptres or more or a difference of 3 dioptres or more between the eyes, with close follow-up.
- Patients should carry glasses as a backup and never wear lenses when the eye is red.

## Next step / Initial management

- Painful red eye, reduced vision or light sensitivity: stop the lens and same-day ophthalmology.
- Mild discomfort without staining: rest from lenses and review in 24 hours.
- Teach hygiene: wash and dry hands, no water on lenses or case, replace the case regularly, no sleeping or swimming in lenses.
- Children starting lenses: review after one week, weekly during the first month, then monthly to the second month (Colombian guideline).

## Test yourself

Think of the answer, then tap the question to see it.

## What is the main modifiable risk for contact lens keratitis?

Sleeping in the lenses (overnight wear), together with poor lens and case hygiene.

## Why should lenses never touch tap water?

Because tap water can carry Acanthamoeba, which causes a severe keratitis.

## Which lenses are used for keratoconus?

Rigid gas-permeable or scleral lenses, which mask the irregular corneal surface.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/ophthalmology/contact-lenses-types-and-complications/)

## Connections

## See it in 3D 1

The structures of Durgical's 3D anatomy where it is found.

- [Cornea](https://durgical.com/en/anatomy/cornea/)

## Related 3

- [Red eye in a contact lens wearer](https://durgical.com/en/ophthalmology/red-eye-in-a-contact-lens-wearer/)
- [Refraction: dioptres and reading a prescription](https://durgical.com/en/ophthalmology/refraction-dioptres-and-reading-a-prescription/)
- [The tear film and ocular surface](https://durgical.com/en/ophthalmology/the-tear-film-and-ocular-surface/)

## Related conditions 3

- [Keratitis and corneal ulcer](https://durgical.com/en/conditions/keratitis-and-corneal-ulcer/)
- [Dry eye disease](https://durgical.com/en/conditions/dry-eye-disease/)
- [Refractive errors and presbyopia](https://durgical.com/en/conditions/refractive-errors-and-presbyopia/)

[← All of ophthalmology](https://durgical.com/en/ophthalmology/)

Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once.

Sources: [Contact Lenses: Principles, Uses and Related Complications](https://www.ncbi.nlm.nih.gov/books/NBK580554/) (StatPearls Publishing (NCBI Bookshelf), 2026); [Acanthamoeba Keratitis](https://www.ncbi.nlm.nih.gov/books/NBK549863/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Guía de práctica clínica para la detección temprana, el diagnóstico, el tratamiento y el seguimiento de los defectos refractivos en menores de 18 años (Guía No. 47)](https://gpc.minsalud.gov.co/gpc_sites/Repositorio/Conv_637/GPC_d_refractivos/gpc_d_refractivos.aspx) (Ministerio de Salud y Protección Social de Colombia, 2016).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/ophthalmology/contact-lenses-types-and-complications/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/ophthalmology/contact-lenses-types-and-complications/