There are many things that can cause your eye to turn red.

The eye looks red when the blood vessels that are in the conjunctiva (the mucous membrane that covers the white of your eye and the backside of your eyelids) becomes dilated.

Those blood vessels often dilate when the eye gets irritated. This irritation can originate from a problem occurring inside the eye or factors from outside the eye.

The most common external factors that can cause the eye to become red are exposure to infectious organisms (mostly viruses and bacteria), environmental irritants (smoke, chemicals, sunlight), or allergens.

Infectious organisms can cause infectious conjunctivitis, or what is more commonly referred to as “pink eye.” This condition often presents with the eye being red and a mucous discharge being produced, often to such a degree that the eyelids are crusted over upon awaking in the morning. Infectious conjunctivitis can be extremely contagious and it is often advised that you...

A common in-office procedure is an eye injection for treatment of various eye conditions, such as wet macular degeneration, diabetic retinopathy, or vein occlusion.  

It is normal to be anxious prior to your first eye injection but knowing what to expect may alleviate some anxiety.  

Your eye will be numbed with topical anesthetic drops. Usually, a cotton-tipped applicator soaked in anesthetic will be held against the white part of the eye to numb it.  Sometimes, a thick gel may also be used for numbing. Once the eye is numbed, it will then be cleaned and a small instrument will be used to hold the eye open. During the actual injection, some patients feel pressure while others may feel a quick sting. Each person will have a different experience and each injection will be different.

The medicine is injected into the white part of the eye. Sometimes a blood vessel may be encountered during the injection and you may notice a little redness on the outside of the eye. This is...