Signs and Symptoms of Keratoconus

Many patients with keratoconus become increasingly sensitive to bright light, a condition called photophobia. Oncoming headlights at night may produce halos, starbursts, or streaks that make driving difficult. Backlit screens, overhead lighting, and reflections off wet pavement can all trigger discomfort. This sensitivity worsens as the cornea becomes steeper and scatters light in more directions across the retina.

Night vision is often one of the first areas where keratoconus creates real-world difficulty. In low light, your pupils dilate and expose more of the irregular corneal surface to incoming light, intensifying halos, ghosting, and distortion. Many patients first seek evaluation after struggling with nighttime driving and finding that they are avoiding highways or unfamiliar roads after dark. If this describes your experience, mentioning it specifically to your eye doctor will help guide the evaluation.

Keratoconus affects both eyes in most cases, but it commonly progresses at different rates in each eye. One eye may produce much more distortion or ghosting than the other, and the difference can be striking. Because we naturally compensate by relying on the better eye, the full extent of change in the more affected eye often goes unnoticed until each eye is tested separately. Describing any differences you notice between your eyes will help your eye doctor track how each one is progressing.

A standard prescription change produces blur that is correctable with new lenses, and the visual image stays as one unified picture. Keratoconus ghosting produces multiple overlapping images or a smeared copy of what you are looking at, and a new prescription reduces but does not eliminate that effect. If your eye doctor comments on irregular astigmatism or difficulty refining your prescription to a sharp endpoint, that is a meaningful signal to pursue topography testing.

The disease itself tends to progress slowly in one direction rather than cycling back and forth. However, dry eye, changes in contact lens fit, humidity, and lighting conditions can cause noticeable day-to-day variation in how clearly you see. If your vision feels better on some days than others, tear film instability may be a contributing factor rather than the keratoconus worsening and improving on its own. Mentioning this pattern to your eye doctor will help sort out the cause.

It is quite common to have noticeably worse symptoms in one eye because keratoconus often progresses at different rates between the two. True single-eye keratoconus is uncommon. Your eye doctor should examine both eyes with topography, because the eye with milder symptoms may still show early corneal changes that are important to monitor and, when appropriate, treat before significant progression occurs.

Keratoconus can appear in early adolescence, and the rate of progression during the teenage years can be faster than in adults. Signs in children can include frequent squinting, difficulty seeing the board at school, holding books or devices very close to the face, and prescription changes that happen within a few months. Children who rub their eyes frequently, especially those with allergies, have a higher risk of developing keratoconus. If any of these patterns describe your child, ask their eye doctor about corneal topography screening.

Early-stage keratoconus is often managed with specialty contact lenses that vault over the irregular corneal surface to provide a smooth optical surface. When the cornea is still progressing, corneal cross-linking, a procedure that uses UV light and riboflavin drops to strengthen corneal tissue, is the primary treatment for slowing or halting the disease. Additional options depending on your corneal shape and vision goals may include Intacs corneal implants, phototherapeutic keratectomy, or amniotic membrane procedures. Your eye doctor will guide which options are appropriate based on your individual findings.

If you experience sudden vision loss, new eye pain that does not ease after removing contact lenses, or visible cloudiness in your cornea, contact your eye doctor the same day. For symptoms that are developing gradually, such as worsening ghosting, night glare, or prescription changes that are happening faster than expected, schedule an evaluation within a few weeks rather than waiting for an annual exam. Earlier evaluation means more options for treatment and preservation of your vision.