Causes of red eyes
Among the causes of redness of the eye : 
- Exposure to air, sunlight, dust, or dust.
- Allergy, inflammation, or some injuries, but sometimes a spot of blood may be observed in the eye, and this is called a subconjunctival hemorrhage, especially if that spot is present without pain, and this spot may disappear after two weeks.
There are several infections that the eye may be exposed to, which is accompanied by itching, pain, and disturbances in vision, including: 
- Eyelid inflammation caused by skin bacteria. This inflammation is accompanied by itching, oily and crusty eyelids.
- Uveitis, which includes inflammation of the iris and the placenta of the eye, and this inflammation is caused by immune diseases, infections, and exposure to toxins, but the inflammation is often limited to the iris.
- Conjunctivitis, which is caused by viral, allergic or bacterial infections, this type of inflammation is highly contagious.
- Corneal ulcers caused by a viral or bacterial infection
- Acute glaucoma, which is a serious condition that results from a sudden high eye pressure.
- Note: These infections can be cured by home care, preparing compresses, not using tools for other infected people, and ensuring that the eyes and hands are clean when touching the eye.
Dangerous eye conditions
If the patient feels one of these cases, he must visit the hospital immediately, which are: 
- Redness of the eye due to a piercing injury.
- Eye redness associated with disturbed vision and headache .
- Redness of the eye associated with seeing halos around the light.
- Redness accompanied by nausea and vomiting.
- Persistent redness for more than a day or two at most.
- Redness accompanied by green or yellowish secretions.